Page 1 Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide Agilent Technologies...
Page 2 Notices Warranty Safety Notices © Agilent Technologies, Inc. 2009–2013 No part of this manual may be reproduced in The material contained in this docu- any form or by any means (including elec- ment is provided “as is,” and is sub-...
Page 3: Safety Symbols
Safety Symbols The following symbols on the instrument and in the documentation indicate precautions which must be taken to maintain safe operation of the instrument. Direct current (DC) Off (supply) Alternating current (AC) On (supply) Both direct and alternating current Caution, risk of electric shock Caution, risk of danger (refer to this manual Three-phase alternating current...
Page 4: Safety Information
Agilent Technologies assumes no liability for the customer’s failure to comply with these requirements. • Turn off the circuit power and discharge all high-voltage capacitors in the circuit before C A U T I O N you perform resistance, continuity, diodes, or capacitance tests.
Page 5 Remove power and do not use the product until safe operation can be verified by service-trained personnel. If necessary, return the product to Agilent Technologies Sales and Service Office for service and repair to ensure the safety features are maintained.
Page 6 Regulatory Markings The C-tick mark is a registered The CE mark is a registered trademark trademark of the Spectrum of the European Community. This CE Management Agency of Australia. This mark shows that the product complies signifies compliance with with all the relevant European Legal the Australia EMC Framework Directives.
Page 7 Technologies, or visit: www.agilent.com/environment/product for more information. Agilent Technologies, through Rechargeable Battery Recycling Corporation (RBRC), offers free and convenient battery recycling options in the U.S. and Canada. Contact RBRC at 877-2-RECYCLE (877.273.2925) or online at: http://www.call2recycle.org/ for the nearest recycling location.
Page 8: In This Guide
In This Guide… Getting Started This chapter contains information on the Agilent U1251B and U1252B handheld multimeter front panel, rotary switch, keypad, display, terminals and rear panel. Making Measurements This chapter contains information on how to make measurements using the U1251B and U1252B handheld digital multimeter. Functions and Features This chapter contains information on the functions and features that are available for the U1251B and U1252B digital multimeter.
Page 9 Declaration of Conformity (DoC) The Declaration of Conformity (DoC) for this instrument is available on the Web site. You can search the DoC by its product model or description. http://regulations.corporate.agilent.com/DoC/search.htm If you are unable to search for the respective DoC, please contact your N O T E local Agilent representative.
Page 10 Agilent U1251B/U1252B User’s and Service Guide...
Page 11: Table Of Contents
Contents Getting Started Introducing the U1251B/U1252B Handheld Digital Multimeter Check the shipment Adjusting the tilt-stand The front panel at a glance The rear panel at a glance The rotary switch at a glance The keypad at a glance The display at a glance Selecting display with the Hz button Selecting display with the Dual button Selecting display with the Shift button...
Page 12 Measuring Temperature Alerts and Warning During Measurement Overload alert Input warning Charge terminal alert Functions and Features Dynamic Recording Data Hold (Trigger Hold) Refresh Hold Null (Relative) Decibel Display 1 ms Peak Hold Data Logging Manual logging Interval logging Reviewing logged data Square Wave Output (for U1252B) Remote Communication Changing The Default Setting...
Page 13 Setting Temperature Unit Setting Auto Power Saving Mode Setting Percentage (%) Scale Readout Setting Beep Frequency Setting Backlight Timer Setting Baud Rate Setting Parity Check Setting Data Bit Setting Echo Mode Setting Print Mode Returning to Default Factory Settings Setting the Battery Voltage Setting the DC Filter Maintenance Introduction...
Page 14 Agilent Technologies calibration services Calibration interval Adjustment is recommended Recommended Test Equipment Basic Operating Test Backlit test Testing the display Current terminal test Charge terminal alert test Test Considerations Calibration Security Performance Verification Tests Unsecuring the instrument for calibration Calibration Process...
Page 15 AC Specifications AC+DC Specifications for U1252B Capacitance Specifications Temperature Specifications Frequency Specifications Duty Cycle and Pulse Width Specifications Frequency Sensitivity Specifications Peak Hold Specifications Frequency Counter Specifications for U1252B Square Wave Output for U1252B Operating Specifications Display update rate (approximate) Input impedance Agilent U1251B/U1252B User’s and Service Guide XVII...
Page 16 XVIII Agilent U1251B/U1252B User’s and Service Guide...
Page 17 List of Figures Figure 1-1 Tilt-stand at 60° Figure 1-2 Tilt-stand at 30° Figure 1-3 Tilt-stand at hanging position Figure 1-4 U1252B front panel Figure 1-5 Rear panel Figure 1-6 Rotary switch Figure 1-7 U1252B keypad Figure 1-8 Display symbols Figure 1-9 Connector terminals Figure 2-1...
Page 18 Figure 3-8 Full Log Figure 3-9 Interval (Automatic) logging mode operation Figure 3-10 Log review mode operation Figure 3-11 Frequency adjustment for square wave output Figure 3-12 Duty cycle adjustment for square wave output Figure 3-13 Pulse width adjustment for square wave output Figure 3-14 Cable connection for remote communication Figure 4-1...
Page 19 List of Tables Table 1-1 Rotary switch description and functions Table 1-2 Keypad descriptions and functions Table 1-3 General display symbols Table 1-4 Primary display symbols Table 1-5 Secondary display symbols Table 1-6 Analog bar range and counts Table 1-7 Selecting display with the Hz button Table 1-8 Selecting display with the Dual button...
Page 20 ber of LSD) for true RMS AC current Table 7-6 U1252B true RMS ac+dc voltage specifications Table 7-7 U1252B true RMS ac+dc current specifications Table 7-8 Capacitance specifications Table 7-9 Temperature specifications Table 7-10 Frequency specifications Table 7-11 Duty cycle and pulse width specifications Table 7-12 Frequency sensitivity and trigger level specifications for voltage measurements...
Page 21 Selecting display with the Dual button Selecting display with the Shift button The terminals at a glance This chapter contains information on the Agilent U1251B and U1252B handheld multimeter front panel, rotary switch, keypad, display, terminals and rear panel. Agilent Technologies...
Page 22: Introducing The U1251B/U1252B Handheld Digital Multimeter
Getting Started Tutorial Introducing the U1251B/U1252B Handheld Digital Multimeter Key features of this digital multimeter: • DC, AC and AC + DC (U1252B only) voltage and current measurements. • True- RMS measurement for both AC voltage and current • Rechargeable Ni- MH battery with built- in charging capability (U1252B only) •...
Page 23: Check The Shipment
Getting Started Tutorial Check the shipment Verify that you have received the following items with your multimeter: • 9 V alkaline battery (U1251B only) • 4 mm probes • Test leads • Alligator clips • Rechargeable 7.2 V battery (U1252B only) •...
Page 24: Adjusting The Tilt-Stand
Getting Started Tutorial Adjusting the tilt-stand ° To adjust the meter to a 60 standing position, pull the tilt- stand outwards to its maximum reach. IR-USB cable To PC (host) ° Tilt-stand at 60 ° Figure 1-1 Tilt-stand at 60 °...
Page 25: Figure 1-3 Tilt-Stand At Hanging Position
Getting Started Tutorial To adjust the meter to a hanging position follow the steps shown in Figure 1- 3 below. 2. Detach the tilt-stand 1. Extend the tilt-stand until its maximum reach 3. Flip the tilt-stand over until this side of the stand is facing the multimeter as 4.
Page 26: The Front Panel At A Glance
Getting Started Tutorial The front panel at a glance Display Keypad Rotary Switch Terminal Connectors Figure 1-4 U1252B front panel Agilent U1251B/U1252B User’s and Service Guide...
Page 27: The Rear Panel At A Glance
Getting Started Tutorial The rear panel at a glance IR Communication Port Test probe holders Tilt-stand Battery access cover Figure 1-5 Rear panel Agilent U1251B/U1252B User’s and Service Guide...
Page 28: The Rotary Switch At A Glance
Getting Started Tutorial The rotary switch at a glance Figure 1-6 Rotary switch Table 1-1 Rotary switch description and functions Description/Function Charge mode (U1252B only) or OFF AC voltage AC voltage, DC voltage or DC+AC voltage (U1252B only) DC mV, AC mV, AC+DC mV (U1252B only) Resistance (Ω), Continuity, and Conductance ( nS ) Frequency counter (U1252B only) or Diode Capacitance or Temperature...
Page 29: The Keypad At A Glance
Getting Started Tutorial The keypad at a glance The operation of each key is shown below. Pressing a key illuminates a related symbol on the display and emits a beep. Turning the rotary switch to another position resets the current operation of the key. Figure 1- 7 below shows the keypad of the U1252B.
Page 30 Getting Started Tutorial Table 1-2 Keypad descriptions and functions (continued) scrolls through available measuring ranges sets to Auto Range mode. (except when rotary switch is set at or at Hz [for U1252B] position) scrolls through available dual-combination exits Hold, Null, Dynamic Recording, 1 ms displays (except when rotary switch is set at Peak Hold and dual display modes.
Page 31: The Display At A Glance
Getting Started Tutorial The display at a glance To view the full display (with all segments illuminated), press and hold button while turning the rotary switch from OFF to any non- OFF position. After you are done viewing the full display, press any button to resume normal functionality based on the rotary switch position.
Page 32: Table 1-3 General Display Symbols
Getting Started Tutorial Table 1-3 General display symbols LCD symbol Description Remote control Thermocouple types: (K-type) (J-type) NULL Null math function Diode / Audible continuity Audible continuity for resistance View mode for checking logged data Data logging indication Square wave output (U1252B only) •...
Page 33: Table 1-4 Primary Display Symbols
Getting Started Tutorial The primary display signs are explained below. Table 1-4 Primary display symbols LCD symbol Description Auto range AC + DC Polarity, digits, and decimal points for primary display Decibel unit relative to 1 mW Decibel unit relative to 1 V MkHz Frequency units: Hz, kHz, MHz Resistance units: Ω, kΩ, MΩ...
Page 34: Table 1-5 Secondary Display Symbols
Getting Started Tutorial The secondary display signs are explained below. Table 1-5 Secondary display symbols LCD symbol Description AC + DC Polarity, digits and decimal points for secondary display Frequency units: Hz, kHz No ambient temperature compensation, just thermocouple measurement ºC Celsius ambient temperature unit ºF...
Page 35: Selecting Display With The Hz Button
Getting Started Tutorial The “+” or “–” sign is indicated when the positive or negative value has been measured or calculated. Each segment represents 2500 or 500 counts depending on the range indicated on the peak bar graph. See the table below. Table 1-6 Analog bar range and counts Range Counts/segments...
Page 36: Table 1-7 Selecting Display With The Hz Button
Getting Started Tutorial display and frequency on the primary display. Alternatively, pulse width (ms) or duty cycle (%) can appear on the primary display by pressing again. This enables the simultaneous monitoring of real- time voltage and current, with frequency, duty cycle or pulse width. Voltage or current measurement resumes on the primary display after you press and hold for more than 1 second.
Page 37: Selecting Display With The Dual Button
Getting Started Tutorial Table 1-7 Selecting display with the Hz button (continued) Frequency (Hz) (DC current) Pulse width (ms) DC µA Duty cycle (%) Frequency (Hz) (AC + DC current) Pulse width (ms) AC + DC µA [for U1252B] Duty cycle (%) Frequency (Hz) (AC current) Pulse width (ms)
Page 38: Table 1-8 Selecting Display With The Dual Button
Getting Started Tutorial Table 1-8 Selecting display with the Dual button Rotary switch position (Function) Primary display Secondary display AC V Hz (AC coupling) (AC voltage) dBm or dBV (select AC V by pressing Ambient temperature °C or °F AC V AC V Hz (AC coupling) dBm or dBV...
Page 39 Getting Started Tutorial Table 1-8 Selecting display with the Dual button (continued) AC + DC mV Hz (AC coupling) (AC + DC voltage) dBm or dBV AC + DC mV [for U1252B] AC + DC mV AC mV AC + DC mV DC mV Ambient temperature °C or °F AC + DC mV...
Page 40: Selecting Display With The Shift Button
Getting Started Tutorial Table 1-8 Selecting display with the Dual button (continued) AC A Hz (AC coupling) (AC current) AC A DC A Ambient temperature °C or °F AC A AC + DC A Hz (AC coupling) (AC + DC current) AC + DC A AC A [for U1252B]...
Page 41 Getting Started Tutorial Table 1-9 Selecting display with the Shift button DC mV for U1252B AC mV (AC + DC Voltage) AC + DC mV Ω Ω Ω (Resistance) Diode (Diode test and Frequency) Capacitance Temperature (Capacitance and Temperature) DC μA AC μA AC + DC μA [for U1252B] (AC Current)
Page 42: The Terminals At A Glance
Getting Started Tutorial The terminals at a glance To avoid damaging the multimeter, do not exceed the input limit. WA R N I N G Figure 1-9 Connector terminals Table 1-10 Terminal connections for different measuring functions Rotary switch position Input terminals Overload protection 1000 V R.M.S.
Page 43: Making Measurements
Measuring Resistance, Conductance and Testing Continuity Testing Diodes Measuring Capacitance Measuring Temperature Alerts and Warning During Measurement Overload alert Input warning Charge terminal alert This chapter contains information on how to make measurements using the U1251B and U1252B handheld digital multimeter. Agilent Technologies...
Page 44: Understanding The Measurement Instructions
2 Making Measurements Understanding The Measurement Instructions When making measurements, follow the numerical steps labelled in the diagrams. Refer to Table 2- 1 below for a description of the steps. Table 2-1 Numerical steps descriptions Instructions Turn the rotary switch to the measurement option shown in the diagram Connect the test leads into the input terminals shown in the diagram Probe the test points Read the results on the display...
Page 45: Measuring Ac Voltage
Making Measurements 2 Measuring AC voltage Set up the multimeter to measure AC voltage as shown in Figure 2- 1. Probe the test points and read the display. Red Lead Black Lead Figure 2-1 Measuring AC voltage Press to display frequency on the secondary display. See Table 1-8 N O T E “Selecting display with the Dual button”...
Page 46: Measuring Dc Voltage
2 Making Measurements Measuring DC voltage Set up the multimeter to measure DC voltage as shown in Figure 2- 2. Probe the test points and read the display. Red Lead Black Lead Figure 2-2 Measuring DC voltage Agilent U1251B/U1252B User’s and Service Guide...
Page 47: Measuring Current
Making Measurements 2 Measuring Current µA & mA measurement Set up the multimeter to measure µA and mA as shown in Figure 2- 3. Probe the test points and read the display. • Press if necessary to ensure is shown on the display. N O T E •...
Page 48: Figure 2-3 Measuring Ma And Ma Current
2 Making Measurements Black Lead Red Lead Figure 2-3 Measuring μA and mA current Agilent U1251B/U1252B User’s and Service Guide...
Page 49: Percentage Scale Of 4 Ma To 20 Ma
Making Measurements 2 Percentage scale of 4 mA to 20 mA Set up the multimeter to measure percentage scale as shown Figure 2- 4. Probe the test points and read the display. • Press to select percentage scale display. Ensure that N O T E is shown on the display.
Page 50: Figure 2-4 Measuring Scale Of 4-20 Ma
2 Making Measurements Black Lead Red Lead Figure 2-4 Measuring scale of 4-20 mA Agilent U1251B/U1252B User’s and Service Guide...
Page 51: A (Ampere) Measurement
Making Measurements 2 A (ampere) measurement Set up the multimeter to measure A (ampere) as shown in Figure 2- 5. Probe the test points and read the display. Connect the red and black test leads to the 10 A input terminal A and COM N O T E respectively.
Page 52: Frequency Counter
2 Making Measurements Frequency Counter • Use the frequency counter for low voltage applications only. WA R N I N G Never use the frequency counter for line power system. • For inputs more than 30 Vpp, you are required to use frequency measurement mode available under the current or voltage measurement instead of frequency counter.
Page 53: Figure 2-6 Measuring Frequency
Making Measurements 2 Black Lead Red Lead Figure 2-6 Measuring frequency Agilent U1251B/U1252B User’s and Service Guide...
Page 54: Measuring Resistance, Conductance And Testing Continuity
2 Making Measurements Measuring Resistance, Conductance and Testing Continuity Disconnect the circuit power and discharge all high-voltage capacitors C A U T I O N before measuring resistance to prevent any possible damage to the multimeter or the device under test. Set up the multimeter to measure resistance as shown in Figure 2- 7.
Page 55: Figure 2-8 Audible Continuity, Conductance, And Resistance
Making Measurements 2 Press to scroll through audible continuity, conductance and resistance tests as shown in Figure 2- Press Audible continuity Press Press Figure 2-8 Audible continuity, conductance, and resistance test. Agilent U1251B/U1252B User’s and Service Guide...
Page 56: Table 2-3 Audible Continuity Measurement Range
2 Making Measurements Audible continuity In the range of 0–500 Ω, the beeper will sound if the resistance value falls below 10 Ω. For other ranges, the beeper will sound if the resistance falls below the typical values indicated in Table 2- 3 below.
Page 57: Figure 2-9 Conductance Measurement
Making Measurements 2 Black Lead Red Lead Figure 2-9 Conductance measurement Agilent U1251B/U1252B User’s and Service Guide...
Page 58: Testing Diodes
2 Making Measurements Testing Diodes Disconnect the circuit power and discharge all the high-voltage capacitors C A U T I O N before testing the diodes to prevent any possible damage to the meter. To test a diode, turn the power off to the circuit and remove the diode from the circuit.
Page 59: Figure 2-10 Measuring Forward Bias Of Diode
Making Measurements 2 Black Lead Red Lead Figure 2-10 Measuring forward bias of diode Agilent U1251B/U1252B User’s and Service Guide...
Page 60: Figure 2-11 Measuring Reverse Bias Of Diode
2 Making Measurements Black Lead Red Lead Figure 2-11 Measuring reverse bias of diode Agilent U1251B/U1252B User’s and Service Guide...
Page 61: Measuring Capacitance
Making Measurements 2 Measuring Capacitance Disconnect the circuit power and discharge all the high-voltage capacitors C A U T I O N before measuring the capacitance to prevent any possible damage to the meter or the device under test. To confirm that the capacitors have discharged, use the DC voltage function.
Page 62: Figure 2-12 Capacitance Measurements
2 Making Measurements Red Lead Black Lead Figure 2-12 Capacitance measurements Agilent U1251B/U1252B User’s and Service Guide...
Page 63: Measuring Temperature
Making Measurements 2 Measuring Temperature Do not bend the thermocouple leads at sharp angles. Repeated bending C A U T I O N over a period of time may break the leads. The bead type thermocouple probe is suitable for making temperature measurements between –20 °C to 200 °C in PTFE compatible environments.
Page 64: Figure 2-13 Connecting The Thermal Probe Into The Non-Compensation Transfer Adapater
2 Making Measurements 8 For a quick measurement, use the 0 °C compensation adapter to see the temperature variation of the thermocouple sensor. The 0 °C compensation adapter assists in measuring the relative temperature immediately. Figure 2-13 Connecting the thermal probe into the non-compensation transfer adapater Figure 2-14 Connecting the probe with adapter into the multimeter Agilent U1251B/U1252B User’s and Service Guide...
Page 65 Making Measurements 2 If you are working in a constantly varying environment, where ambient temperatures are not constant, do the following: 1 Press to select 0 °C compensation. This gives a quick measurement of the relative temperature. 2 Avoid contact between the thermocouple probe and the measurement surface.
Page 66: Figure 2-15 Surface Temperature Measurement
2 Making Measurements Figure 2-15 Surface temperature measurement Agilent U1251B/U1252B User’s and Service Guide...
Page 67: Alerts And Warning During Measurement
Making Measurements 2 Alerts and Warning During Measurement Overload alert For your safety, look out for this alert. When you are alerted, WA R N I N G immediately remove the test leads from the measuring source. The meter provides an overload alert for voltage measurements in both auto and manual range modes.
Page 68: Charge Terminal Alert
2 Making Measurements Charge terminal alert The meter sounds an alert beep when the terminal detects a voltage level of more than 5 V and the rotary switch is not set to the corresponding location. The primary display indicates a flashing “Ch.Err” until the lead is removed from the input terminal.
Page 69: Functions And Features
1 ms Peak Hold Data Logging Manual logging Interval logging Reviewing logged data Square Wave Output (for U1252B) Remote Communication This chapter contains information on the functions and features that are available for the U1251B and U1252B digital multimeter. Agilent Technologies...
Page 70: Dynamic Recording
Features and Functions Dynamic Recording The Dynamic Recording mode can be used to detect intermittent turn- on or turn- off voltage, current surges or to verify measurement performance without you being present during the process. While the readings are being recorded, you are free to perform other tasks.
Page 71: Figure 3-1 Dynamic Recording Mode Operation
Features and Functions Press Max Min Press Max Min for > 1 sec Press Max Min for > 1 sec or press for > 1 sec Press Max Min Press Max Min for > 1 sec or press for > 1 sec Press Max Min Press Max Min for >...
Page 72: Data Hold (Trigger Hold)
Features and Functions Data Hold (Trigger Hold) The data hold function allows the user to freeze the displayed digital value. 1 Press to freeze the displayed value and to enter the manual trigger mode. TRIG is displayed. 2 Press again to freeze the next value being measured.
Page 73: Refresh Hold
Features and Functions Refresh Hold The Refresh Hold function allows you to hold the displayed value. The bar- graph is not held and will continue to reflect the instantaneous measured value. You can use the Setup mode to enable Refresh Hold mode when you are working with fluctuating values.
Page 74: Figure 3-3 Refresh Hold Mode Operation
Features and Functions Press Variation counts > setting The HOLD sign flashes until the measured value is stable and updated Measurement is updated Press to return Figure 3-3 Refresh hold mode operation • For voltage and current measurements, the holding value will not be N O T E updated if the reading is below 500 counts.
Page 75: Null (Relative)
Features and Functions Null (Relative) The Null function subtracts a stored value from the present measurement and displays the difference between the two. 1 Press to store the displayed reading as the reference value to be subtracted from subsequent measurements and to set the display to zero. NULL is displayed.
Page 76: Figure 3-4 Null (Relative) Mode Operation
Features and Functions Press Press Auto-return after 3 seconds Flash Press as NULL is flashing on the display Figure 3-4 Null (relative) mode operation Agilent U1251B/U1252B User’s and Service Guide...
Page 77: Decibel Display
Features and Functions Decibel Display The dBm operation calculates the power delivered to a reference resistance relative to 1 mW and can be applied to DC V, AC V and AC + DC V measurements for decibel conversion. The voltage measurement is converted to dBm by using the following formula: The reference resistance may be selected from 1~9999 Ω...
Page 78: Figure 3-5 Dbm/Dbv Display Mode Operation
Features and Functions Press Only when rotary switch is at position Press Press for > 1 sec. Press for > 1 sec. Press Press Press for > 1 sec. Only when rotary switch is at Press position Press Press Press Figure 3-5 dBm/dBV display mode operation Agilent U1251B/U1252B User’s and Service Guide...
Page 79: Ms Peak Hold
Features and Functions 1 ms Peak Hold The Peak Hold function allows the measurement of peak voltage for analysis of components such as power distribution transformers and power factor correction capacitors. The peak voltage obtained can be used to determine the crest factor: Crest factor = Peak value/True RMS value 1 Press for more than 1 second to toggle 1 ms Peak...
Page 80: Figure 3-6 1 Ms Peak Hold Mode Operation
Features and Functions Press for > 1 sec. Press Start to capture Start to capture Press Press Press Figure 3-6 1 ms peak hold mode operation Agilent U1251B/U1252B User’s and Service Guide...
Page 81: Data Logging
Features and Functions Data Logging The data logging function provides the convenience of recording test data for future review or analysis. Since data is stored in nonvolatile memory, the data remains saved even if the multimeter is turned OFF or the battery is changed.
Page 82: Figure 3-7 Hand (Manual) Logging Mode Operation
Features and Functions Press for > 1 sec. Press for > 1 sec. Auto-return after 3 seconds Figure 3-7 Hand (Manual) logging mode operation The maximum data that can be stored is 100 entries. When the 100 entries N O T E are filled, the secondary display indicates “FULL”, as shown in Figure 3-8.
Page 83: Interval Logging
Features and Functions Interval logging Firstly, ensure that interval (time) logging is specified in Setup mode. 1 Press for more than 1 second to store the present value and function on the primary display into the non- volatile memory. The and the logging index will be indicated.
Page 84: Figure 3-9 Interval (Automatic) Logging Mode Operation
Features and Functions Press for > 1 sec. First interval Press for > 1 sec. Last interval Press for > 1 sec. Last +1 interval Stop logging Figure 3-9 Interval (Automatic) logging mode operation Agilent U1251B/U1252B User’s and Service Guide...
Page 85: Reviewing Logged Data
Features and Functions Reviewing logged data 1 Press for more than 1 second to enter the Log Review mode. The last recorded entry and the last logging index are displayed. 2 Press to switch between hand (manual) and interval (automatic) logging review mode. 3 Press to ascend or to descend through the logged...
Page 86: Figure 3-10 Log Review Mode Operation
Features and Functions Press View for > 1 sec. Press View Press Press Press Press Press Press Press View Press Press Press Press Press View Press Press Press Log to clear all Press Log to clear all for > 1 sec manual logs for >...
Page 87: Square Wave Output (For U1252B)
Features and Functions Square Wave Output (for U1252B) The square wave output function can be used to generate a PWM (pulse width modulation) output or provide a synchronous clock source (baud rate generator). You can also use this function to check and calibrate flow- meter displays, counters, tachometers, oscilloscopes, frequency converters, frequency transmitters, and other frequency input devices.
Page 88: Figure 3-11 Frequency Adjustment For Square Wave Output
Features and Functions Press Press Press Press Set Hz Figure 3-11 Frequency adjustment for square wave output 5 Press to select the pulse width (ms) on the primary display. 6 Press to adjust the pulse width. The pulse width can be set for 256 steps and each step is 1/ (256 x Frequency).
Page 89: Figure 3-12 Duty Cycle Adjustment For Square Wave Output
Features and Functions Press Press Press Press Figure 3-12 Duty cycle adjustment for square wave output Agilent U1251B/U1252B User’s and Service Guide...
Page 90: Figure 3-13 Pulse Width Adjustment For Square Wave Output
Features and Functions Press Press Press Press Figure 3-13 Pulse width adjustment for square wave output Agilent U1251B/U1252B User’s and Service Guide...
Page 91: Remote Communication
Features and Functions Remote Communication The meter has a bi- directional (full duplex) communication capability that speeds data storing from the meter to the PC. To use this feature, you require the optional IR- USB cable, to be used with an application software downloadable from the Agilent Web site.
Page 92 Features and Functions Agilent U1251B/U1252B User’s and Service Guide...
Page 93 Setting Echo Mode Setting Print Mode Returning to Default Factory Settings Setting the Battery Voltage Setting the DC Filter This chapter shows you how to change the default factory settings of the U1251B and U1252B and other available setting options. Agilent Technologies...
Page 94: Changing The Default Setting
Changing The Default Setting Selecting Setup Mode To enter the Setup mode, perform the following steps: 1 Turn the meter OFF. 2 From the OFF position, press and hold while turning the rotary switch to any non- OFF position. When you hear a beep, the meter is in Setup mode and you can release N O T E To change a menu item setting in Setup mode, perform the following steps:...
Page 95: Table 4-1 Available Setting Options In Setup Mode
Changing The Default Setting Table 4-1 Available setting options in Setup mode Menu item Available setting options Default factory setting Display Description Display Description Enables Data Hold (manual trigger) Sets the variation rHoLd Refresh Hold count that determines 100–1000 Refresh Hold (auto trigger) Enables DC filter when FiLtE...
Page 96 Changing The Default Setting Table 4-1 Available setting options in Setup mode (continued) Menu item Available setting options Default factory setting Display Description Display Description Sets the timer for the auto turn-off for the 1–99 s backlit display b-Lit 30 s Backlit display Disables the auto turn-off for the backlit...
Page 97 Changing The Default Setting Table 4-1 Available setting options in Setup mode (continued) Menu item Available setting options Default factory setting Display Description Display Description Sets the temperature measurement to °C but d-CF pressing swaps the display to °F Sets the temperature measurement to °F Temperature Sets the temperature...
Page 98: Setting Data Hold/Refresh Hold Mode
Changing The Default Setting Setting Data Hold/Refresh Hold Mode 1 Set OFF to enable the Data Hold mode (manual trigger by key or bus via the remote control). 2 Set the variation count within the 100~1000 range to enable the Refresh Hold mode (auto trigger). When the variation of the measuring value exceeds the setting of the variation count, the Refresh Hold will be ready to trigger.
Page 99: Setting Data Logging Mode
Changing The Default Setting Setting Data Logging Mode 1 Set to “Hand” to enable the manual data logging mode. 2 Set the interval within 0001—9999 seconds to enable interval (automatic) data logging mode. 3 Press and hold for more than 1 second to switch between manual and interval data logging setup.
Page 100: Setting Thermocouple Types (U1252B Only)
Changing The Default Setting Setting Thermocouple Types (U1252B only) The thermocouple sensor types that can be selected are type K (default) or type J. Press to switch between the J and the K type. Press Figure 4-3 Thermocouple type setup Agilent U1251B/U1252B User’s and Service Guide...
Page 101: Setting Reference Impedance For Dbm Measurement
Changing The Default Setting Setting Reference Impedance for dBm Measurement The reference impedance can be set from 1 to 9999 W. The default value is 50 W. Press Press Press Press Figure 4-4 Reference impedance for dBm measurement setup Agilent U1251B/U1252B User’s and Service Guide...
Page 102: Setting Minimum Frequency Measurement
Changing The Default Setting Setting Minimum Frequency Measurement The minimum frequency setup influences the measuring rates for frequency, duty cycle and pulse width. The typical measuring rate is based on the minimum frequency of 1 Hz. Press Press Press Press Press Figure 4-5 Minimum frequency setup Agilent U1251B/U1252B User’s and Service Guide...
Page 103: Setting Temperature Unit
Changing The Default Setting Setting Temperature Unit Four combination displays are available: • Celsius only (°C on primary display) single display setting • Celsius- Fahrenheit (d- CF) and Fahrenheit- Celsius (d- FC) dual display setting. Primary-Secondary Display can be swapped by pressing N O T E •...
Page 104: Figure 4-6 Temperature Unit Setup
Changing The Default Setting Press Press Press Press Press Figure 4-6 Temperature unit setup Agilent U1251B/U1252B User’s and Service Guide...
Page 105: Setting Auto Power Saving Mode
Changing The Default Setting Setting Auto Power Saving Mode • The timer for APF (Auto Power OFF) can be set for the range of 1—99 minutes. • To activate the meter after it has “auto powered- off”, turn the rotary switch to the OFF position. Then turn it back on again.
Page 106: Figure 4-7 Auto Power Saving Setup
Changing The Default Setting Press Press Press Press Press Figure 4-7 Auto power saving setup Agilent U1251B/U1252B User’s and Service Guide...
Page 107: Setting Percentage (%) Scale Readout
Changing The Default Setting Setting Percentage (%) Scale Readout This setting converts the DC current measuring display to percentage (%) scale readout — 4–20 mA or 0–20 mA as proportional to 0~100%. The 25% scale readout represents DC 8 mA at 4–20 mA and DC 5 mA at 0–20 mA. Press Figure 4-8 % scale readout setup Agilent U1251B/U1252B User’s and Service Guide...
Page 108: Setting Beep Frequency
Changing The Default Setting Setting Beep Frequency The driving frequency can be set to 2400, 1200, 600, or 300Hz. “OFF” disables the beep. Press Press Press Press Press Press Figure 4-9 Beep frequency setup Agilent U1251B/U1252B User’s and Service Guide...
Page 109: Setting Backlight Timer
Changing The Default Setting Setting Backlight Timer • The timer can be set to 1—99 seconds. The backlight will turn off automatically after the set period. • “0FF” disables turning off backlit automatically. Press Press Press Press Press Figure 4-10 Backlit timer setup Agilent U1251B/U1252B User’s and Service Guide...
Page 110: Setting Baud Rate
Changing The Default Setting Setting Baud Rate Select the baud rate for remote control. The available settings are 2400, 4800, 9600, and 19200 Hz. Press Press Press Press Press Figure 4-11 Baud rate setup remote control Agilent U1251B/U1252B User’s and Service Guide...
Page 111: Setting Parity Check
Changing The Default Setting Setting Parity Check Select the parity check for remote control. It can be set to none, even, or odd bit. Press Press Press Press Figure 4-12 Parity check setup Agilent U1251B/U1252B User’s and Service Guide...
Page 112: Setting Data Bit
Changing The Default Setting Setting Data Bit Select the data bit for remote control. It can be set to either 8 or 7 bits. Press Figure 4-13 Data bit setup for remote control Agilent U1251B/U1252B User’s and Service Guide...
Page 113: Setting Echo Mode
Changing The Default Setting Setting Echo Mode • Echo ON enables the return of characters to the PC in remote communication. • Echo OFF disables the return of characters to the PC. Press Figure 4-14 Echo mode setup for remote control Agilent U1251B/U1252B User’s and Service Guide...
Page 114: Setting Print Mode
Changing The Default Setting Setting Print Mode Print ON enables the printing of measured data to the PC when the measuring cycle is completed. In this mode, the meter automatically sends the newest data to the host continuously but does not accept any commands from the host.
Page 115: Returning To Default Factory Settings
Changing The Default Setting Returning to Default Factory Settings • Press for more than 1 second to reset to the default factory settings all menu options except the Temperature setting. • The Reset menu item automatically reverts to Refresh Hold menu item after reset has taken place. Press for >...
Page 116: Setting The Battery Voltage
Changing The Default Setting Setting the Battery Voltage Battery type for the multimeter can be set to either 7.2 V or 8.4 V. Press Figure 4-17 Battery voltage selection Agilent U1251B/U1252B User’s and Service Guide...
Page 117: Setting The Dc Filter
Changing The Default Setting Setting the DC Filter This setting is used to filter AC signals in DC measuring paths. The DC filter is set to “OFF” by default. To enable this function, set this to “On”. Press Figure 4-18 DC filter •...
Page 118 Changing The Default Setting Agilent U1251B/U1252B User’s and Service Guide...
Page 119: Maintenance
General maintenance Battery replacement Storage considerations Charging the battery Fuse checking procedure Replacing the fuse Troubleshooting Replaceable Parts To order replaceable parts This chapter will go through how to troubleshoot the handheld digital multimeter if any problems arise. Agilent Technologies...
Page 120: Introduction
Maintenance Introduction Any repair or service which is not covered in this manual should only C A U T I O N be performed by qualified personnel. General maintenance Ensure that the terminal connections are correct for that particular WA R N I N G measurement before proceeding.
Page 121 Maintenance 1 At the rear panel, turn the screw on the battery cover from the LOCK to the OPEN position (counterclockwise). 2 Slide down the battery cover. 3 Lift the battery cover up. 4 Replace the specified battery. 5 Reverse the above steps to close the cover. List of compatible batteries for the Agilent U1251B : N O T E •...
Page 122: Storage Considerations
Maintenance List of compatible batteries for the Agilent U1252B : N O T E • 9 V size 300mAH Ni-MH rechargeable battery, 7.2 V nominal voltage • 9 V size 300mAH Ni-MH rechargeable battery, 8.4 V nominal voltage • 9 V Alkaline non-chargeable battery (ANSI/NEDA 1604A or IEC 6LR61) •...
Page 123: Charging The Battery
Maintenance Charging the battery Never discharge the battery by shorting it or by reverse polarity in any WA R N I N G subjects. Make sure the battery is the rechargeable type before charging it. Never rotate the rotary switch when the battery is being charged as DC at 24 V is being applied to the charging terminals.
Page 124: Table 5-1 Battery Voltage And Corresponding Percentage Of Charg
Maintenance Use the specified 24 V DC adaptor to charge the battery. Remember never to turn the rotary switch of the meter when its battery is being charged. Use the following steps to charge the battery: 1 Disconnect the test leads from the meter. 2 Turn the rotary switch to the position.
Page 125: Figure 5-2 Battery Capacity Display As Trickle
Maintenance Figure 5-2 Battery capacity display as trickle 5 After pressing SHIFT or when the self- test starts, the meter performs a self- test to check if the battery in the meter is the rechargeable type. The self- test takes about 2 to 3 minutes.
Page 126: Figure 5-3 Self-Test
Maintenance Figure 5-3 Self-test Table 5-2 Error messages Error Error message 1 No battery inside 2 Faulty battery 3 Battery is fully charged Error Error message Agilent U1251B/U1252B User’s and Service Guide...
Page 127 Maintenance Table 5-2 Error messages (continued) C-Err 1 If charging battery more than 12 V or less than 5 V 2 In 3 minutes, if the battery voltage does not go upwards then charge error • If the OL message appears while the battery is inside, do not charge the battery. N O T E •...
Page 128: Figure 5-4 Charging Mode
Maintenance Figure 5-4 Charging mode 7 The charge end message (C–End) appears on the secondary display once charging is completed. The trickle charging current is provided to maintain the battery capacity. The flashing signs of appear to show the trickle state. 8 Remove the DC adapter when the C–End message appears on the secondary display.
Page 129: Figure 5-6 Battery Charging Procedure
Maintenance Press to start charge Error-Full Error Error Error-Empty Battery can be charged Fully charged Figure 5-6 Battery charging procedure Agilent U1251B/U1252B User’s and Service Guide...
Page 130: Fuse Checking Procedure
Maintenance Fuse checking procedure It is recommended that you check the fuses of the multimeter before using it. Follow the instructions below to test the fuses inside the multimeter. Refer to Figure 5- 8 for the respective positions of Fuse 1 and Fuse 2. 1 Set the rotary switch to 2 Connect the red test lead to the input terminal Figure 5-7 Fuse checking procedures...
Page 131: Table 5-3 Measurement Readings For Fuse Checking
Maintenance 3 To test Fuse 1, place the tip of the test probe on the right half of input terminal . Ensure that the probe tip touches the metal inside the input terminal, as shown in the figure above. 4 To test Fuse 2, place and touch the tip of the test probe on the right half of input terminal .
Page 132: Replacing The Fuse
Maintenance Replacing the fuse This manual provides only the fuse replacement procedures, but not the N O T E fuse replacement markings. Follow the procedures below to replace the fuse. 1 Turn the meter off and disconnect the test leads from the external equipment.
Page 133: Figure 5-8 Fuse Replacement
Maintenance Table 5-4 Fuse specifications Fuse Agilent part number Rating Size Type 2110-1400 440mA/1000V 10 mm x 35 mm Fast blow Fuse 2110-1402 11A/1000V 10 mm x 38 mm Fuse 1 Fuse 2 Figure 5-8 Fuse replacement Agilent U1251B/U1252B User’s and Service Guide...
Page 134: Troubleshooting
Maintenance Troubleshooting To avoid electrical shock, do not perform any service on the device unless WA R N I N G you are qualified to do so. If the instrument fails to operate, check the battery and the test leads. Replace them if necessary. And if the instrument still does not function, check the operating procedures in this manual.
Page 135: Replaceable Parts
Maintenance Replaceable Parts This section contains information for ordering replacement parts for your instrument. You can find the instrument support part list at Agilent’s Test & Measurement Parts Catalog at: http://www.agilent.com/find/parts This parts list includes a brief description of each part with applicable Agilent part number.
Page 136 Maintenance Agilent U1251B/U1252B User’s and Service Guide...
Page 137 Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide Performance Tests and Calibration Calibration Overview Closed-case electronic calibration Agilent Technologies calibration services Calibration interval Adjustment is recommended Recommended Test Equipment Basic Operating Test Backlit test Testing the display...
Page 138: Performance Tests And Calibration
The nonvolatile EEPROM calibration memory is retained even when the power is switched off. Agilent Technologies calibration services When your instrument is due for calibration, contact your local Agilent Service Center to enquire about recalibration services.
Page 139: Calibration Interval
Performance Tests and Calibration Calibration interval A 1- year interval is adequate for most applications. Accuracy specifications are warranted only if adjustment is made at regular calibration intervals. Accuracy specifications are not warranted beyond the 1- year calibration interval. Agilent does not recommend extending calibration intervals beyond 2 years for any application.
Page 140: Recommended Test Equipment
Performance Tests and Calibration Recommended Test Equipment The test equipment recommended for the performance verification and adjustment procedures is listed below. If the exact instrument is not available, substitute calibration standards of equivalent accuracy. A suggested alternative method would be to use the Agilent 3458A 8½...
Page 141: Basic Operating Test
Performance Tests and Calibration Basic Operating Test The Basic Operating Test is to test the basic operability of the instrument. Repair is required if the instrument fails the Basic Operating Test. Backlit test Press the Bat button to test the backlight. It will momentarily toggle backlit ON and OFF.
Page 142: Current Terminal Test
Performance Tests and Calibration Current terminal test This test determines if the input warning of the current terminal test is functioning properly. The meter sounds an alert beep when the test lead is inserted into the A terminal but the rotary switch is not set to mA.A function.
Page 143: Charge Terminal Alert Test
Performance Tests and Calibration Charge terminal alert test This test determines if the charge terminal alert is operating properly. The meter sounds an alert when the terminal detects a voltage level of more than 5 V and the rotary switch is not set to the position.
Page 144: Test Considerations
Performance Tests and Calibration Test Considerations Long test leads can also act as antennas which may pick up AC signals. For optimum performance, all procedures should comply with the following recommendations: • Ensure that the calibration ambient temperature is stable and is between 18 °C and 28 °C.
Page 145: Calibration Security
Performance Tests and Calibration Calibration Security The calibration security code prevents accidental or unauthorized adjustments to the instrument. When you first receive your instrument, it is secured. Before you can adjust the instrument, you must unsecure it by entering the correct security code (see “Unsecuring the instrument for calibration”...
Page 146: Performance Verification Tests
Performance Tests and Calibration Performance Verification Tests Use the Performance Verification Tests to verify the measurement performance of the instrument. The performance verification tests use the instrument’s specifications listed in the U1251B/U1252B Data Sheet. The performance verification tests are recommended as acceptance tests when you first receive the instrument.
Page 147: Table 6-2 Verification Test
Performance Tests and Calibration Perform the verification test steps in the following Table 6- Table 6-2 Verification Test Error from nominal 1 year Step Test Function Range 5520A Output U1251B U1252B Turn the rotary switch to the 5 V, 1 kHz ±...
Page 148 Performance Tests and Calibration Error from nominal 1 year Step Test Function Range 5520A Output U1251B U1252B Turn the rotary switch to ± 2 mV ± 1.75 mV position (for model U1252B), to position (for model U1251B) 50 V 50 V ±...
Page 149 Performance Tests and Calibration Error from nominal 1 year Step Test Function Range 5520A Output U1251B U1252B Press button to go to 50 mV 50 mV, 1 kHz ± 0.34 mV ± 0.24 mV mV mode 50 mV, 10 kHz ±...
Page 150 Performance Tests and Calibration Error from nominal 1 year Step Test Function Range 5520A Output U1251B U1252B Turn the rotary switch to the W 500 W 500 W ± 350 m ± 500 mW position ± 4.5 W ± 3 W 5 kW 5 kW ±...
Page 151 Performance Tests and Calibration Error from nominal 1 year Step Test Function Range 5520A Output U1251B U1252B 1000.0 μF 1000.0 μF ± 10.5 μF ± 10.5 μF 10.00 mF 10.00 mF ± 0.105 mF ± 0.105 mF 100.00 mF 10.00 mF ±...
Page 152: Performance Tests And Calibration
Performance Tests and Calibration Error from nominal 1 year Step Test Function Range 5520A Output U1251B U1252B Press button to go to 5 A, 1 kHz ± 42 mA ± 37 mA A mode 3 A, 5 kHz ± 96 mA ±...
Page 153 Performance Tests and Calibration 10 10 A continuous, and additional 0.5% to specified accuracy when measuring a signal greater than 10 A~20 A for 30 seconds maximum. After measured current for > 10 A, to cool down the meter for twice the measuring time you applied before low current measurement.
Page 154: Unsecuring The Instrument For Calibration
Performance Tests and Calibration Unsecuring the instrument for calibration Before you can adjust the instrument, you must unsecure it by entering the correct security code. The security code is set to 1234 when the instrument is shipped from the factory. The security code is stored in nonvolatile memory, and does not change when power is off.
Page 155 Performance Tests and Calibration To change the instrument calibration security code from the front panel 1 When the multimeter is in the unsecured mode, press for more than 1 second to enter the Calibration Security Code setting mode. 2 The factory default calibration security code 1234 will be displayed on the primary display.
Page 156 Performance Tests and Calibration To unsecure the instrument without the security code To unsecure the instrument without the correct security code, follow the steps below. If you do not have a record of the security code, you can try 1234 (the fac- N O T E tory default code) using the front panel.
Page 157: Calibration Process
Performance Tests and Calibration Calibration Process To complete a full instrument calibration use following general procedures: 1 Read “Test Considerations” on page 124. 2 Perform the verification tests to characterize the instrument (incoming data). 3 Unsecure the instrument for calibration (see “Calibration Security”...
Page 158: Using The Front Panel For Adjustments
Performance Tests and Calibration Using the front panel for adjustments This section describes the procedures to perform adjustments from the front panel. Selecting the Adjustment Mode To unsecure the instrument, see “Unsecuring the instrument for calibration” on page 134 or “To unsecure the instrument without the security code”...
Page 159: Adjustments Consideration
Performance Tests and Calibration Adjustments Consideration You will need a test input cable, a connectors set, and a Shorting Plug to adjust the instrument. After each adjustment, the secondary display briefly shows PASS. If the N O T E calibration fails, the handheld multimeter sounds a beep, and an error number is shown in the secondary display.
Page 160: Valid Adjustment Input Values
Performance Tests and Calibration Valid adjustment input values Adjustment can be accomplished using the following input values below. Table 6-3 Valid adjustment input values Function Range Valid Amplitude Input Values 5 V, 50 V, 500 V, 1000 V 0.9 to 1.1 x Full Scale 5 V, 50 V, 500 V, 1000 V 0.9 to 1.1 x Full Scale (for U1251B)
Page 161: Adjustment Procedure
Performance Tests and Calibration Adjustment Procedure Review the sections “Test Considerations” on page 124 and “Adjustments Consideration” on page 139 before proceeding with this procedure. 1 Turn the rotary switch to “Test Function” position as shown in the adjustment table. 2 After unsecuring the instrument, the instrument goes into the adjustment mode.
Page 162 Performance Tests and Calibration For an adjustment that is successful, the secondary display will briefly show PASS. An adjustment failure is indicated by a long beep and a calibration error number appears in the secondary display. The primary display remains at the current Cal Item.
Page 163: Table 6-4 Adjustment Table
Performance Tests and Calibration For serial numbers below MY51530001, the 10 kHz input frequency is N O T E applied to those marked with an asterix (*) Table 6-4 Adjustment table Cal Item Step Test Function Cal Range Input U1251B U1252B Turn the rotary switch to the 0.3 V,1 kHz...
Page 164 Performance Tests and Calibration Cal Item Step Test Function Cal Range Input U1251B U1252B Press button to go to 0.3 V, 1 kHz 0.3000 V V mode 3 V, 1 kHz 3.0000 V 3 V, 20 kHz * 3.0000 V 50 V 3 V, 1 kHz 03.000 V...
Page 165 Performance Tests and Calibration Cal Item Step Test Function Cal Range Input U1251B U1252B Press button to go to 50 mV 3 mV, 1 kHz 03.000 mV 03.000 mV mV mode 30 mV, 1 kHz 30.000 mV 30.000 mV 30 mV, 20 kHz * 30.000 mV 30.000 mV 500 mV...
Page 166 Performance Tests and Calibration Cal Item Step Test Function Cal Range Input U1251B U1252B Turn the rotary switch to the Hz/ Short Dual banana SHORT SHORT position (for model shorting plug with U1252B), to position (for copper wire model U1251B) 2.0000 V 2.0000 V Turn the rotary switch to the...
Page 167 Performance Tests and Calibration Cal Item Step Test Function Cal Range Input U1251B U1252B Press button to go to 500 µA 30 µA,1 kHz 030.00 µA 030.00 µA µA mode 300 µA,1 kHz 300.00 uA 300.00 µA 5000 µA 300 µA,1 kHz 0300.0 µA 0300.0 µA 3000 µA, 1 kHz...
Page 168: Finishing The Adjustment
Performance Tests and Calibration Notes for adjustment table: 1 Be sure to recalibrate “Short” using the dual banana plug with copper wire after performing calibration for resistance. 2 Ensure the multimeter is turned on and stabilized for at least 60 minutes, with the K-type thermocouple connected between the multimeter and the calibrator output terminal.
Page 169: Calibration Errors
Performance Tests and Calibration 1 Press Adjustment Mode. The primary display shows the calibration count. 2 Take note of the count. 3 Press again to exit the calibration count mode. Calibration Errors The following errors indicate failures that may occur during a calibration.
Page 170 Performance Tests and Calibration Agilent U1251B/U1252B User’s and Service Guide...
Page 171: Specifications
Peak Hold Specifications Frequency Counter Specifications for U1252B Square Wave Output for U1252B Operating Specifications Display update rate (approximate) Input impedance This chapter lists the product characteristics, specification assumptions and the specifications of the U1251B and U1252B digital multimeters. Agilent Technologies...
Page 172: Product Characteristics
Specifications Product Characteristics POWER SUPPLY Battery type: • 9 V size Ni-MH rechargeable battery, 7.2 V nominal voltage • 9 V size Ni-MH rechargeable battery, 8.4 V nominal voltage • 9 V Alkaline battery (ANSI/NEDA 1604A or IEC 6LR61) • 9 V Carbon-zinc battery (ANSI/NEDA 1604D or IEC6F22) Battery life: •...
Page 173 Specifications SAFETY COMPLIANCE • EN/IEC 61010-1:2001 • ANSI/UL 61010-1:2004 • CAN/CSA-C22.2 No. 61010-1-04 MEASUREMENT CATEGORY CAT III 1000 V/CAT IV 600 V Overvoltage Protection EMC COMPLIANCE • Certified to IEC61326-1:2005 / EN61326-1:2006 • CISPR 11:2003 / EN 55011:2007 Group 1 Class A •...
Page 174 Specifications WARRANTY Please refer to http://www.agilent.com/go/warranty_terms • Three years for the product • Three months for the product's standard accessories, unless otherwise specified Please take note that for the product, the warranty does not cover: • Damage from contamination • Normal wear and tear of mechanical components •...
Page 175: Measurement Category
Specifications Measurement Category The Agilent U1251B and U1252B Handheld Digital Multimeter has a safety rating of CAT III 1000 V/ CAT IV, 600 V. Measurement category definition Measurement CAT I are measurements performed on circuits which are not directly connected to the AC mains. For example, measurements on circuits not derived from the AC mains or specially protected (internal) mains- derived circuits.
Page 176: Specification Assumptions
Specifications Specification Assumptions • The DC specifications are defined for measurements which are taken after at least 1 minute of warm- up time. • The AC and AC+DC specifications are defined for measurements of sine wave and are taken after at least 1 minute of warm- up time.
Page 177: Table 7-1 Dc Accuracy ± (% Of Reading + Number Of Least Signifi- Cant Digit)
Specifications Table 7-1 DC Accuracy ± (% of reading + Number of Least Significant Digit) (continued) Test Current/ Accuracy Function Range Resolution Burden Voltage U1251B U1252B 500.00 Ω 0.01 Ω 1.04 mA 0.08 + 10 0.05 + 10 5.0000 kΩ 0.0001 kΩ...
Page 178 Specifications Table 7-1 DC Accuracy ± (% of reading + Number of Least Significant Digit) (continued) Test Current/ Accuracy Function Range Resolution Burden Voltage U1251B U1252B 500.00 µA 0.01 µA 0.06 V 0.1 + 5 0.05 + 5 5000.0 µA 0.1 µA 0.6 V 0.1 + 5...
Page 179: Ac Specifications
Specifications AC Specifications AC specifications for U1251B Table 7-2 U1251B accuracy specifications ± (% of reading + number of LSD) for true RMS AC voltage Frequency Function Range Resolution 30 Hz to 45 Hz 45 Hz to 1 kHz 1 kHz to 5 kHz 5 kHz to 30 kHz 50.000 mV 0.001 mV...
Page 180 Specifications AC specifications for U1252B Table 7-4 U1252B accuracy specifications ± (% of reading + number of LSD) for true RMS AC voltage Frequency 20 Hz – 45 Hz – 1 kHz – 5 kHz – 15 kHz – Function Range Resolution 45 Hz...
Page 181: Ac+Dc Specifications For U1252B
Specifications AC+DC Specifications for U1252B Table 7-6 U1252B true RMS ac+dc voltage specifications Frequency 30 Hz – 45 Hz – 1 kHz – 5 kHz – 15 kHz – Function Range Resolution 45 Hz 1 kHz 5 kHz 15 kHz 100kHz 50.000 mV 0.001 mV...
Page 182: Capacitance Specifications
Specifications Capacitance Specifications Table 7-8 Capacitance specifications Accuracy ± Range Resolution (% of reading + Offset Display update rate (approx) Error) 10.000 nF 0.001 nF 1% + 8 100.00 nF 0.01 nF 1000.0 nF 0.1 nF 10.000 µF 0.001 µF 4 times/sec.
Page 183: Frequency Specifications
Specifications Table 7-9 Temperature specifications Notes for temperature specifications: 1 Accuracy of specifications is subject to the following conditions: • The accuracy does not include the tolerance of the thermocouple probe. The thermal sensor plugged into the meter should be placed in the operating environment for at least an hour. •...
Page 184: Frequency Sensitivity Specifications
Specifications Table 7-11 Duty cycle and pulse width specifications Function Mode Range Resolution Accuracy (at full scale) Notes for duty cycle specifications: 1 The accuracy for duty cycle and pulse width is based on a 5 V square wave input into the DC 5 V range. 2 For AC coupling, the duty cycle range can be measured for signal frequency >...
Page 185: Table 7-13 Frequency Sensitivity Specifications For Current
Specifications Table 7-12 Frequency sensitivity and trigger level specifications for voltage measurements Minimum sensitivity (RMS sine wave) Trigger level for DC coupling Model Number Input U1251B U1252B U1251B U1252B range 20 Hz - 100 >100 kHz - 20 Hz - 200 >200 kHz - >100 kHz - >...
Page 186: Peak Hold Specifications
Specifications Peak Hold Specifications Table 7-14 Peak hold specifications for dc voltage and current measurements Signal Width Accuracy For DC mV/voltage/current Single event > 1 ms 2% + 400 for all ranges Repetitive > 250 µs 2% + 1000 for all ranges Frequency Counter Specifications for U1252B Table 7-15 Frequency counter (divide by 1) specifications Accuracy...
Page 187: Square Wave Output For U1252B
Specifications Table 7-16 Frequency counter (divide by 100 ) specifications Accuracy ± (% of reading + No. Range Resolution Sensitivity Min. Input Frequency of Least Significant Digit) 9.9999 MHz 0.0001 MHz 0.002 % + 5, 400 mV R.M.S. 1 MHz 99.99 MHz 0.001 MHz 600 mV R.M.S.
Page 188 Specifications Table 7-17 Square wave output specifications Notes for square wave output specifications: 1 Output impedance: 3.5 kW maximum. 2 The positive or negative pulse width must be greater than 50 µs for adjusting the duty cycle or the pulse width under different frequencies.
Page 189: Operating Specifications
Specifications Operating Specifications Display update rate (approximate) Table 7-18 Display update rate (approximate) Function Times/second AC V AC V + dB DC V (V or mV) AC V (V or mV) AC+DC V (V or mV) Ω / nS Diode Capacitance 4 (<...
Page 190: Input Impedance
Specifications Input impedance Table 7-19 Input Impedance Function Range Input Impedance 50.000 mV 10.00 MΩ 500.00 mV 10.00 MΩ 1000.0 mV 10.00 MΩ [1] [3] DC Voltage 5.0000 V 11.10 MΩ 50.000 V 10.10 MΩ 500.00 V 10.01 MΩ 1000.0 V 10.001 MΩ...
Page 191 Product specifications and descriptions in this document are subject to change with- out notice. Always refer to the Agilent Web site for the latest revision. © Agilent Technologies, Inc. 2009–2013 Printed in Malaysia Tenth Edition, March 7, 2013 U1251-90036 Agilent Technologies...

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U1251b

Agilent Technologies U1252B User's Manual And Service Manual

1 Getting Started

2 Making Measurements

3 Functions and Features

4 Changing the Default Setting

5 Maintenance

6 Performance Tests and Calibration

Performance Tests and Calibration

7 Specifications

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