Agilent Technologies U1251A User's And Service Manual
  1. Manuals
  2. Brands
  3. Agilent Technologies Manuals
  4. Multimeter
  5. U1251A
  6. User's and service manual

Agilent Technologies U1251A User's And Service Manual

Handheld digital multimeter
Hide thumbs Also See for U1251A:
Table of Contents

Advertisement

Quick Links

Download this manual See also: User Manual and Service Information, User Manual
Agilent U1251A and
U1252A
Handheld Digital
Multimeter
User's and Service Guide
Agilent Technologies

Advertisement

Table of Contents
loading

Related Manuals for Agilent Technologies U1251A

Summary of Contents for Agilent Technologies U1251A

  • Page 1 Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Agilent Technologies...
  • Page 2 FAR 12.211 (Technical Data) and 12.212 (Computer Software) and, for the Department of Defense, DFARS 252.227-7015 (Technical Data - Commercial Items) and DFARS 227.7202-3 (Rights in Commercial Computer Software or Com- puter Software Documentation). Agilent U1251A/U1252A User’s and Service Guide...
  • Page 3 This is to avoid false readings, which may lead to possible electric shock or personal injury. • Do not operate the product in an explosive atmosphere or in the presence of flammable gases or fumes. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 4 • Do not substitute parts or modify equipment to avoid the danger of introducing additional hazards. Return the product to Agilent Technologies Sales and Service Office for service and repair to ensure the safety features are maintained •...
  • Page 5 Safety Symbols Category III 1000 V Overvoltage Protection CAT III 1000 V Double insulation Earth ground Caution, risk of danger (Refer to the User’s and Service Guide for details) Caution, risk of electric shock Agilent U1251A/U1252A User’s and Service Guide...
  • Page 6 Australia EMC Framework regulations under the terms of the Radio Communication Act of 1992. This instrument complies with the WEEE Directive (2002/96/EC) marking requirement. This affixed product label indicates that you must not discard this electrical/electronic product in domestic household waste. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 7 This DoC applies to above-listed products placed on the EU market after: 22-August-2006 Date Mack Soh Quality Manager For further information, please contact your local Agilent Technologies sales office, agent or distributor, or Agilent Technologies Deutschland GmbH, Herrenberger Straße 130, D 71034 Böblingen, Germany. Template: A5971-5302-2, Rev. B.01 U1251A Rev 1.0...
  • Page 8 Regulatory Information for Canada ICES/NMB-001:1998 This ISM device complies with Canadian ICES-001. Cet appareil ISM est confomre à la norme NMB-001 du Canada. Regulatory Information for Australia/New Zealand This ISM device complies with Australian/New Zealand AS/NZS 2064.1 Agilent U1251A/U1252A User’s and Service Guide...

  • Page 9: Table Of Contents

    Contents Getting Started Tutorial Introducing the Agilent U1251A and U1252A Handheld Digital Multimeter Adjusting the Tilt-Stand The Front Panel at a Glance The Rotary Switch at a Glance The Keypad at a Glance The Display at a Glance Selection of Display by Hz Button...
  • Page 10 Setting Beep Frequency Setting Backlit Timer Setting Baud Rate Setting Parity Check Setting Data Bit Setting Echo Mode Setting Print Mode Returning to Default Factory Settings Maintenance Introduction General Maintenance Battery Replacement Charging Battery Fuse Replacement Agilent U1251A/U1252A User’s and Service Guide...
  • Page 11 Calibration Process Using the Front Panel for Adjustments Adjustments Consideration Valid Adjustment Input Values Adjustment Procedure Finishing the Adjustment To Read the Calibration Count Calibration Errors Specifications DC Specifications U1251A AC Specifications U1252A AC Specifications Agilent U1251A/U1252A User’s and Service Guide...
  • Page 12 Contents U1252A AC+DC Specifications Temperature and Capacitance Specifications U1251A & U1252A Frequency Specifications(1) Operating Specifications General Specifications Agilent U1251A/U1252A User’s and Service Guide...

  • Page 13: Getting Started Tutorial

    Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Getting Started Tutorial Introducing the Agilent U1251A and U1252A Handheld Digital Multimeter Adjusting the Tilt-Stand The Front Panel at a Glance The Rotary Switch at a Glance The Keypad at a Glance...

  • Page 14: Introducing The Agilent U1251A And U1252A Handheld Digital Multimeter

    Getting Started Tutorial Introducing the Agilent U1251A and U1252A Handheld Digital Multimeter The handheld digital multimeters’ key features are: • DC, AC and AC + DC (only U1252A) voltage and current measurements. • True- RMS measurement for both AC voltage and current •...

  • Page 15: Adjusting The Tilt-Stand

    To adjust the meter to a 30 standing position, bend the tip of the stand so that it is parallel to ground before pulling the stand outwards to its maximum reach. IR-USB cable To PC (host) Tilt-stand at 30 º Agilent U1251A/U1252A User’s and Service Guide...
  • Page 16 Then flip the stand over so that the stand’s inner surface is facing the meter’s rear. Now, press the stand down into its hinge. Follow the step by step pictorial instructions below. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 17: The Front Panel At A Glance

    Getting Started Tutorial The Front Panel at a Glance Display Display Keypad Rotary switch Terminals Agilent U1251A/U1252A User’s and Service Guide...

  • Page 18: The Rotary Switch At A Glance

    Frequency counter [U1252A only] or Diode Capacitance or Temperature DC µA and AC µA DC mA, DC current, AC mA or AC current Square-wave output, Duty cycle or Pulse width output [for U1252A] and OFF [for U1251A] Agilent U1251A/U1252A User’s and Service Guide...

  • Page 19: The Keypad At A Glance

    1 ms Peak Hold mode. Push subtracted from subsequent measurements. Push to scroll through Max and Min peak readings. again to see the relative value that has been saved. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 20 For pulse and duty cycle measurement, push to switch trigger slope to positive or negative. When meter is in peak or dynamic-recording mode, push to restart 1 ms peak hold or dynamic recording mode. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 21: The Display At A Glance

    3 For U1252A only, rotary switch at square wave out position, press only DUAL, RANGE and HOLD buttons or turn the rotary switch to other position. The LCD signs are described on page 22, 23 and 24. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 22 Dynamic Recording mode: Minimum value on primary display Dynamic Recording mode: Average value on primary display 1ms Peak Hold mode: Positive peak value on primary display 1ms Peak Hold mode: Negative peak value on primary display Agilent U1251A/U1252A User’s and Service Guide...
  • Page 23 Duty cycle measurement Pulse width unit µmnF Capacitance units: nF, µF, mF ºC Celsius temperature unit ºF Fahrenheit temperature unit Percentage scale readout proportional to DC 0–20 mA Percentage scale readout proportional to DC 4–20 mA Agilent U1251A/U1252A User’s and Service Guide...
  • Page 24 When 4–20 mA% scale or 0–20 mA% scale is indicated on the primary display, the bar graph represents the current value. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 25: Selection Of Display By Hz Button

    Selection of Display by Hz Button The frequency measuring helps to detect the presence of harmonic currents in neutral conductors and determines whether these neutral currents are the result of unbalanced phases or non- linear loads. Pushing enters Frequency Agilent U1251A/U1252A User’s and Service Guide...
  • Page 26 Pulse width (ms) Duty cycle (%) Frequency (Hz) AC + DC mV (AC + DC voltage) Pulse width (ms) [for U1252A] Duty cycle (%) Frequency (Hz) AC µA (AC Current) Pulse width (ms) Duty cycle (%) Agilent U1251A/U1252A User’s and Service Guide...

  • Page 27: Selection Of Display By Dual Button

    100 [for U1252A] Selection of Display by Dual Button Push to select different combinations of dual display. Normal single display resumes after you push and hold for more than 1 second. See table below. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 28 Ambient temperature °C or °F DC mV [1] Reading of dBm or dBV depends on the last review on AC V. If the last N O TE review is dBV, the following display will also remain in dBV. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 29 Ambient temperature °C or °F AC + DC mA DC A Hz (DC coupling) (DC current) DC A AC A Ambient temperature °C or °F DC A AC A Hz (AC coupling) (AC current) AC A DC A Agilent U1251A/U1252A User’s and Service Guide...

  • Page 30: Selection Of Display By Shift Button

    (in dual display mode) DC V for U1251A for U1252A DC V (AC + DC Voltage) AC V AC + DC V for U1252A DC mV (AC + DC Voltage) AC mV AC + DC mV Agilent U1251A/U1252A User’s and Service Guide...
  • Page 31 Square wave output for Duty cycle (%) Pulse width (ms) U1252A N O TE 1. Push to switch between dBm and dBV measurement. Push for more than 1 second to return to AC V measurement only. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 32: The Terminals At A Glance

    1000 V R.M.S. for short circuit <0.3 A Ω μA . mA 440 mA / 1000 V 30 kA fast-acting fuse 11 A / 1000 V 30 kA fast-acting fuse for U1252A 440 mA / 1000 V fast-acting fuse Agilent U1251A/U1252A User’s and Service Guide...

  • Page 33: The Rear Panel At A Glance

    Getting Started Tutorial The Rear Panel at a Glance communication port Test probe holders Battery access cover Figure 3 Rear panel of U1252A Agilent U1251A/U1252A User’s and Service Guide...
  • Page 34 Getting Started Tutorial Agilent U1251A/U1252A User’s and Service Guide...

  • Page 35: Making Measurements

    Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Making Measurements Measuring Voltage Measuring AC voltage Measuring DC voltage Measuring Current μA & mA Measurement % Scale of 4–20 mA A measurement Frequency Counter Measuring Resistance, Conductance and Testing Continuity...

  • Page 36: Measuring Voltage

    1 Set the rotary switch to 2 Connect the red and black test leads to input terminals V.mV and COM respectively. 3 Alternatively, push to display frequency on secondary display. 4 Probe the test points and read the display. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 37 Making Measurements 2 Figure 3 Measuring AC voltage Agilent U1251A/U1252A User’s and Service Guide...

  • Page 38: Measuring Dc Voltage

    Figure 4 Measuring DC voltage Measuring DC voltage 1 Set the rotary switch to 2 Connect the red and black test leads to input terminals V.mV and COM respectively. 3 Probe the test points and read the display. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 39: Measuring Current

    2 Connect the red and black test leads to input terminals μA.mA and COM respectively. 3 Probe the test points in series with the circuit, and read the display. Figure 5 Measuring μA and mA current Agilent U1251A/U1252A User’s and Service Guide...

  • Page 40: Scale Of 4-20 Ma

    The % scale for 4–20 mA or 0–20 mA is set to two ranges as follows: % (0–20 or 4–20 mA) Always auto range DC mA Auto or manual range 999.99% 50 mA, 500 mA 9999.9% Figure 6 Measuring scale of 4-20 mA Agilent U1251A/U1252A User’s and Service Guide...

  • Page 41: A Measurement

    2 Connect the red and black test leads to 10A input terminal A and COM respectively. The meter is set to A measurement automatically when the red test lead is plugged into the A terminal. Figure 7 A measurement Agilent U1251A/U1252A User’s and Service Guide...

  • Page 42: Frequency Counter

    6 The signal is out of specification if the reading is still unstable after Step 5. While the secondary display shows “- 1- “, you may scroll through the pulse width (ms), duty cycle (%) and frequency (Hz) measurements by pushing Agilent U1251A/U1252A User’s and Service Guide...
  • Page 43 Making Measurements 2 Push Figure 8 Measuring frequency Agilent U1251A/U1252A User’s and Service Guide...

  • Page 44: Measuring Resistance, Conductance And Testing Continuity

    1 Set the rotary switch to Ω 2 Connect the red and black test leads to input terminals Ω and COM respectively. 3 Probe the test points (by shunting the resistor) and read the display. Figure 9 Measuring resistance Agilent U1251A/U1252A User’s and Service Guide...
  • Page 45 Making Measurements 2 4 Push to scroll through audible continuity, conductance and resistance tests as shown in Figure 10. Audible continuity Figure 10 Audible continuity, conductance and resistance test. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 46 Conductance measurement eases measurement of very high resistance of up to 100 GΩ. As high- resistance readings are susceptible to noise, you can capture average readings via the Dynamic Recording mode. See Figure 17 on Page 59. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 47 Making Measurements 2 Figure 11 Conductance measurement Agilent U1251A/U1252A User’s and Service Guide...

  • Page 48: Testing Diodes

    • Diode is considered shorted if the meter displays approximately 0 V in both forward and reverse bias modes, and the meter beeps continuously. • Diode is considered open if the meter displays “OL” in both forward and reverse bias modes. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 49 Making Measurements 2 Figure 12 Measuring forward bias of diode Agilent U1251A/U1252A User’s and Service Guide...
  • Page 50 Making Measurements Figure 13 Measuring reverse bias of diode Agilent U1251A/U1252A User’s and Service Guide...

  • Page 51: Measuring Capacitance

    2 Connect the red and black test leads to input terminals and COM respectively. 3 Use the red probe lead on the positive terminal of the capacitor while the black probe lead on the negative terminal. 4 Read the display. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 52: Measuring Temperature

    • For quick measurement, use the 0 °C compensation to see the temperature variation of the thermocouple sensor. The 0 °C compensation assists you in measuring relative temperature immediately. 1 Turn the rotary switch to TEMP position. 2 Push to select temperature measurement. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 53 3 After a constant reading is obtained, push to set the reading as the relative reference temperature. 4 Touch the measurement surface with the thermocouple probe. 5 Read the display for the relative temperature. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 54 Making Measurements Press Figure 14 Surface temperature measurement Agilent U1251A/U1252A User’s and Service Guide...

  • Page 55: Alerts And Warning During Measurement

    A input terminal but the rotary switch is not set to the corresponding mA.A location. The primary display indicates a flashing “A- Err” until the test lead is removed from the A input terminal. See Figure 15. Figure 15 Input terminal warning Agilent U1251A/U1252A User’s and Service Guide...

  • Page 56: Charge Terminal Alert

    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 input terminal. See Figure 16. Figure 16 Charge terminal alert Agilent U1251A/U1252A User’s and Service Guide...

  • Page 57: Features And Functions

    Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Features and Functions 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 U1252A)

  • Page 58: Dynamic Recording

    • The average value is the true average of all measured values taken in the Dynamic Recording mode. If an overload is recorded, the averaging function will stop and the average value becomes "OL"(overload). is disabled in Dynamic Recording mode. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 59 Push MAX MIN Push MAX MIN for >1 s or Push for >1 s Push MAX MIN Push MAX MIN for >1 s or Push for >1 s Figure 17 Dynamic recording mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 60: Data Hold (Trigger Hold)

    TRIG flashes before the new value is updated onto the display. 3 Push and hold for more than 1 second to quit this mode. Figure 18 Data hold mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 61: Refresh Hold

    The hold value will be updated until the measuring value is stable, and then it stops flashing and lit and sound a tone to remind user. Press again to disable this function. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 62 • For resistance and diode measurements, the holding value will not be updated if the reading is in “OL” (open state). • The holding value may not be updated when the reading does not reach the stable state for all measurements. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 63: Null (Relative)

    • When in DC voltage measurement, the thermal effect will influence the accuracy. Short the test leads and push NULL once the displayed value is stable in order to zero out the display. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 64 Features and Functions Figure 20 Null (relative) mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 65: Decibel Display

    The dBm or dBV measurement can be selected at ACV position, the selection will be the reference for other voltage measurement. 2 Push for more than 1 second to exit this mode. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 66 Features and Functions Figure 21 dBm/dBV display mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 67: Ms Peak Hold

    • If you need to re-start peak recording, push 3 Push for more than 1 second to exit this mode. 4 According measurements in Figure 22, the crest Factor will be 2.5048/1.768 =1.416. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 68 Features and Functions Figure 22 1 ms peak hold mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 69: Data Logging

    The logging index flashes on the secondary display for 3 seconds before returning to normal display. 2 Push again for the next value that you want to save into memory. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 70 Maximum data that can be stored is 100 entries. When the 100 entries are N O TE filled, “FULL” is indicated on the secondary display, as shown in Figure 24. Figure 24 Full Log 3 Push for more than 1 second to exit this mode. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 71: Interval Logging

    “FULL” is indicated on the secondary display. 2 Push for more than 1 second to exit this mode. When interval (automatic) logging is enabled, all keypad operation is N O TE disabled, except for LOG function. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 72 Features and Functions Figure 25 Interval (Automatic) logging mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 73: Reviewing Logged Data

    Review mode to clear logged data. 5 Push for more than 1 second to exit mode. During data review in either manual or interval logging mode, push button for more than one second to clear all logging values, respectively. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 74 Features and Functions Figure 26 Log review mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 75: Square Wave Output (For U1252A)

    (ms) on primary display. 4 Push to adjust the duty cycle. Duty cycle can be set for 256 steps and each step is 0.390625%. The display only indicates the best resolution with 0.001%. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 76 6 Push to adjust the pulse width. The pulse width can be set for 256 steps and each step is 1/ (256 x Frequency). The display range auto- adjusts in the range of 9.9999~9999.9 ms. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 77 Features and Functions Figure 28 Duty cycle adjustment for square wave output Agilent U1251A/U1252A User’s and Service Guide...
  • Page 78 Features and Functions Figure 29 Pulse width adjustment for Square Wave Agilent U1251A/U1252A User’s and Service Guide...

  • Page 79: Remote Communication

    USB- RS232 together with the application software in the accompanying Refer to the “Agilent GUI Software Helpfile” in the CD for instructions on how to perform the PC- meter remote communication. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 80: Remote Communication

    Features and Functions To PC USB Figure 30 Cable Connection for remote communication Agilent U1251A/U1252A User’s and Service Guide...

  • Page 81: Changing The Default Setting

    Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Changing The Default Setting Selecting Setup Mode Setting Data Logging Mode Setting Thermocouple Types (for U1252A) Setting Reference Impedance for dBm Measurement Setting Minimum Frequency Measurement Setting Temperature Unit...

  • Page 82: Selecting Setup Mode

    Table 3, “Available setting options in Setup mode,” for details of available options. 3. Push to save changes. These parameters remain in the non- volatile memory. 4. Push for more than 1 second to exit Setup mode. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 83 (remote control with PC) dAtAb 7-bit, 8-bit Sets data bit length for remote communication 8-bit Data bits (remote control with PC) ECHO ON, OFF Enables return of characters to PC when set to Echo Agilent U1251A/U1252A User’s and Service Guide...
  • Page 84 N O TE 2. For d-LoG and rEF menu items, push to select the digit to be adjusted. 3. J-type thermocouple applies to U1252A. 4. To view tEMP menu item, push for more than 1 second. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 85 2. Set variation count within 100~1000 range to enable Refresh Hold mode (automatic trigger). When the variation of measuring value exceeds the setting of variation count, the Refresh Hold will be ready to trigger. Figure 31 Data hold/Refersh hold setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 86: Setting Data Logging Mode

    1. Set “Hand” to enable hand (manual) data logging mode. 2. Set interval within 0001~9999 seconds to enable interval (automatic) data logging mode. 3. Push to switch between manual and interval data logging setup. Figure 32 Data logging setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 87: Setting Thermocouple Types (For U1252A)

    Setting Thermocouple Types (for U1252A) The types of thermocouple sensor that can be selected are J and K types. Default type is K type. Push switch between J and K type. Figure 33 Thermocouple type setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 88: 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 . The default value is 50 Figure 34 Reference impedance for dBm measurement setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 89: Setting Minimum Frequency Measurement

    The minimum frequency setup influences the measuring rates for frequency, duty cycle, and pulse width. Typical measuring rate defined at the general specification is based on the minimum frequency of 1 Hz. Figure 35 Minimum frequency setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 90: Setting Temperature Unit

    • 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 pushing N O TE • Fahrenheit only (°F on primary display) single display setting. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 91 Changing The Default Setting Figure 36 Temperature unit setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 92: Setting Auto Power Saving Mode

    1~99 minutes. To activate the meter after it has auto power off, turn the rotary switch to the OFF position, then turn it back on again. • “OFF” means disables APF. is indicated on the display during subsequent measurements. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 93 Changing The Default Setting Figure 37 Auto power saving setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 94: Setting % 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. Figure 38 % scale readout setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 95: Setting Beep Frequency

    Changing The Default Setting Setting Beep Frequency • The driving frequency can be set to 2400, 1200, 600 or 300 Hz. “OFF” disables beep. Figure 39 Beep frequency setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 96: Setting Backlit Timer

    Changing The Default Setting Setting Backlit Timer • Timer can be set to 1~99 seconds. Backlit turns off automatically after the set period. • “0FF” disables turning off backlit automatically. Figure 40 Backlit timer setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 97: Setting Baud Rate

    Changing The Default Setting Setting Baud Rate The baud rate is selected for remote control. The available settings are 2400, 4800, 9600 and 19200 Hz. Figure 41 Baud rate setup remote control Agilent U1251A/U1252A User’s and Service Guide...

  • Page 98: Setting Parity Check

    Changing The Default Setting Setting Parity Check The parity check is selected for remote control. It can be set to either none, even or odd bit. Figure 42 Parity check setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 99: Setting Data Bit

    Changing The Default Setting Setting Data Bit Data bit is selected for remote control. It can be set to either 8 or 7 bits. Figure 43 Data bit setup for remote control Agilent U1251A/U1252A User’s and Service Guide...

  • Page 100: Setting Echo Mode

    Changing The Default Setting Setting Echo Mode • Echo ON enables return of characters to PC in remote communication. • Echo OFF disables Echo mode. Figure 44 Echo mode setup for remote control Agilent U1251A/U1252A User’s and Service Guide...

  • Page 101: Setting Print Mode

    In this mode, the meter automatically sends the newest data to the host continuously but does not accept any commands from the host. flashes during Print operation. Figure 45 Print mode setup for remote control Agilent U1251A/U1252A User’s and Service Guide...

  • Page 102: Returning To Default Factory Settings

    1 second to reset to default factory settings except the Temperature setting. • The Reset menu item automatically reverts to Refresh Hold menu item after reset has taken place. Figure 46 Reset setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 103: Maintenance

    Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Maintenance Introduction General Maintenance Battery Replacement Charging Battery Fuse Replacement Troubleshooting This chapter will help you troubleshoot a failing handheld digital multimeter. Agilent Technologies...

  • Page 104: Introduction

    3 Wipe the case with a damp cloth and mild detergent — do not use abrasives or solvents. Wipe the contacts in each terminal with a clean swab dipped in alcohol. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 105: Battery Replacement

    “Charging The Battery”. Below is the procedures for battery replacement: 1 At the rear panel, turn the screw on the battery cover from LOCK to OPEN position (counterclockwise). Agilent U1251A/U1252A User’s and Service Guide...

  • Page 106: Charging Battery

    “COM” terminals, respectively. The DC adaptor can be replaced with a DC power supply, in order to set a DC24V output and the over current limitation to <0.5A. Ensure the polarity of the connection is correct. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 107 90%. Condition Battery Voltage Proportional Percentage Trickle (SBY) 6.0 V ~ 8.2 V 0% ~ 100% Under charging 7.2 V ~ 10.0 V 0% ~ 100% Figure 47 Battery capacity display as trickle Agilent U1251A/U1252A User’s and Service Guide...
  • Page 108 The self- test will take about 2- 3 minutes. Avoid from operating any push buttons during the self- test. An error message is diplayed shown below. Figure 48 Self test Agilent U1251A/U1252A User’s and Service Guide...
  • Page 109 Maintenance Error Condition Secondary Display • No battery in the meter • Battery failing • Battery is full C-Err • No rechargeable battery inside • Battery failing Figure 49 Error messages Agilent U1251A/U1252A User’s and Service Guide...
  • Page 110 During the charging in progress, no pushbuttons can be operated. The error message maybe indicated during charging to prevent overcharging on the battery. Figure 50 Charging mode Agilent U1251A/U1252A User’s and Service Guide...
  • Page 111 8. Remove the DC adapter when the C–End is displayed on the secondary display. Do not turn the rotary switch before removing the adapter from the terminals. Figure 51 Charge end and trickle state Agilent U1251A/U1252A User’s and Service Guide...
  • Page 112 Maintenance Figure 52 Battery charging procedures Agilent U1251A/U1252A User’s and Service Guide...

  • Page 113: Fuse Replacement

    10 Refer to the table below for the part number, rate and size of the fuses. 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 Agilent U1251A/U1252A User’s and Service Guide...
  • Page 114 Maintenance Fuse 1 Fuse 2 Figure 53 Fuse replacement Agilent U1251A/U1252A User’s and Service Guide...

  • Page 115: Troubleshooting

    • The optical side of cable connected to meter, the text side of cover should Failed on Remote control be up. • Check the baud rate, parity, Data bit, Stop bit (default is 9600, n, 8, 1) • Driver install for USB- RS232. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 116 Maintenance Agilent U1251A/U1252A User’s and Service Guide...

  • Page 117: Accessories

    Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Accessories Checking the Shipping Contents List of Accessories This chapter contains information on the standard and optional accessories. It includes the shipping contents along with this instrument. Agilent Technologies...

  • Page 118: Checking The Shipping Contents

    • Standard Test Lead Kit • Quick Start Guide • CD containing the User’s Guide, application software and instrument drivers • Certificate of Calibration If anything is missing, contact your nearest Agilent Sales Office. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 119: List Of Accessories

    Mini Grabber (black only) Optional U1180A T/C Adapter, non-compensation transfer adap- T/C bead, K type T/C bead, J type U1161A Medium Jaw Alligator Clips Extension Lead set Extension Test Probe Banana Plug U1173A IR-USB Cable Agilent U1251A/U1252A User’s and Service Guide...
  • Page 120 Accessories Agilent U1251A/U1252A User’s and Service Guide...

  • Page 121: Performance Tests And Calibration

    Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Performance Tests and Calibration Calibration Overview Recommended Test Equipment Basic Operating Test Test Considerations Performance Verification Tests Calibration Security Calibration Process Adjustments Consideration This chapter contains performance test procedures and adjustment procedures.

  • Page 122: Calibration Overview

    Agilent to provide this service at competitive prices. 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 Agilent U1251A/U1252A User’s and Service Guide...

  • Page 123: Adjustment Is Recommended

    Agilent recommends that complete re- adjustment should always be performed at the calibration interval. This will assure that the U1251A/U1252A will remain within specification for the next calibration interval. This criteria for re- adjustment provides the best long –term stability.

  • Page 124: Recommended Test Equipment

    <1/5 instrument 1 year spec Square Wave Agilent 53131A and Agilent 34401A <1/5 instrument 1 year spec Short Shorting Plug - Dual banana plug with copper <1/5 instrument 1 year spec wire short between 2 terminal Agilent U1251A/U1252A User’s and Service Guide...

  • Page 125: Basic Operating Test

    ON and OFF. Testing the Display Press the button and turn on the Meter to view all segments of the display. Compare the display with the example in Figure 1. Figure 54 LCD display Agilent U1251A/U1252A User’s and Service Guide...

  • Page 126: Current Terminal Test

    Figure 55. The primary display will keep flashing unless the test lead is removed from “A” terminal. Before conducting this test, make sure the beep function is not disabled in N O TE setup. Figure 55 Input warning Agilent U1251A/U1252A User’s and Service Guide...

  • Page 127: Charge Terminal Alert Test

    “Ch.Err” until the lead is removed from terminal. Figure 56 Charge terminal alert Before conducting this test, make sure the beep function is not disabled in N O TE setup. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 128: Test Considerations

    For the DC voltage, DC current, and resistance gain verification measurements, you should ensure the calibrator's "0" output is correct. You will need to set the offset for each range of the measuring function being verified. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 129: Input Connections

    Teflon interconnect cables of minimum length are recommended between the calibrator and the multimeter. Cable shields should be earth ground referenced. This configuration is recommended for optimal noises and settling time performance during calibration. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 130: Performance Verification Tests

    ‘guard band’, using not more than 80% of the specifications, as the verification limits. Make sure you have read “Test Considerations” on page 128 before doing N O TE the performance verification tests. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 131 Perform the verification test steps in the following Table 5: Table 5 Verification Test Step Test Function Range 5520A Output Error from nominal 1 year U1251A U1252A Turn the rotary switch to the 5 V, 1 kHz ± 32.5 mV ± 22.5 mV V position 5 V, 10 kHz ±...
  • Page 132 ± 415 mV 50 V, 100 kHz ± 1.87 V 500 V 500 V, 1 kHz ± 2.25 V 500 V, 10 kHz ± 2.25 V 1000 V 1000 V, 1 kHz ± 8.0 V Agilent U1251A/U1252A User’s and Service Guide...
  • Page 133 ± 6.5 mV 1000 mV, 10 kHz ± 12.5 mV ± 6.5 mV 1000 mV, 20 kHz ± 11.5 mV 1000 mV, 30 kHz ± 20.0 mV 1000 mV, 100 kHz ± 47.0 mV Agilent U1251A/U1252A User’s and Service Guide...
  • Page 134 ± 0.108 nF TEMP/ position 100.00 nF 100.00 nF ± 1.05 nF ± 1.05 nF 1000.0 nF 1000.0 nF ± 10.5 nF ± 10.5 nF 10.000 μF 10.000 μF ± 0.105 μF ± 0.105 μF Agilent U1251A/U1252A User’s and Service Guide...
  • Page 135 ± 3.0 mA Caution:Connect calibrator to hanheld multimeter's A and COM terminal before applying 5A and 10A ± 16 mA ± 16 mA [10] 10 A 10 A ± 40 mA ± 35 mA Agilent U1251A/U1252A User’s and Service Guide...
  • Page 136 ± 260 mHz [12] Duty Cycle 100 Hz @ 50% ± 0.398% [12] 100 Hz @ 25% ± 0.398% [12] 100 Hz @ 75% ± 0.398% Use 34410A Amplitude 4800 Hz @ ± 0.2V 99.609% Agilent U1251A/U1252A User’s and Service Guide...
  • Page 137 After measured current for > 10A, to cool down the meter for 2 times of measuring time you applied before low current measurement [12] For signal frequency greater than 1 kHz, additional 0.1% per kHz to be added to accuracy Agilent U1251A/U1252A User’s and Service Guide...

  • Page 138: Calibration Security

    The security code may contain up to 4 numeric characters. “To Unsecure the Instrument Without the Security Code” on page 141 N O TE if you forget your security code. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 139: Unsecuring The Instrument For Calibration

    4 Use the editing keys to step each character in the code. Use the to select each character. 5 Press (Save) when done. 6 If the correct security code is entered, the secondary display will show PASS. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 140 5 Press (Save) button, to store new calibration security code. 6 If the new calibration security code has been successfully store, the secondary display will show PASS. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 141 7. Set the code, same as last 4 digit serial number of the instrument. 8. Press (Save) button, to confirm the entry. 9. If the correct 4 digit serial number was entered, the secondary display briefly show PASS. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 142: Calibration Process

    5 Secure the instrument against calibration. 6 Note the new security code and calibration count in the instrument's maintenance records. Make sure to quit the Adjustment Mode then turn off the instrument. N O TE Agilent U1251A/U1252A User’s and Service Guide...

  • Page 143: Using The Front Panel For Adjustments

    1 Use the edit keys to select each digit in the primary display. 2 Use the arrow keys to advance through the digits 0 through 9. 3 Press when done to start calibration. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 144: Adjustments Consideration

    1 hour with K- type thermocouple connected between instrument and calibration source. Never turn off the instrument during an adjustment. This may delete the CAU T ION calibration memory for the present function. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 145: Valid Adjustment Input Values

    500 Ω, 5kΩ, 50 kΩ,500 kΩ, 5MΩ, 50 MΩ / TEMP 10 nF, 100 nF, 1000 nF, 10 F, 100 Make sure to provide 0 °C with µ µ 1000 F, 10 mF / 0 °C µ ambient compensation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 146: Adjustment Procedure

    7 Enter the actual applied input (see “Entering Adjustment Values” on page 143). 8 Press to start the adjustment. The CAL flashes in the secondary display to indicate the calibration is in progress. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 147 9 Repeat steps 1 through 8 for each adjustment point. 10 Verify the adjustments using the “Performance Verification Tests” on page 130. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 148 V position (for model U1252A), to short between 2 V position (for model terminals U1251A) 3.0000 V 3.0000 V 30 V 30.000 V 30.000 V 500V 300 V 300.00 V 300.00 V 1000V 1000 V 1000.0 V 1000.0 V Agilent U1251A/U1252A User’s and Service Guide...
  • Page 149 SHort mV position with copper wire short between 2 terminals 50 mV 30 mV 30.000 mV 30.000 mV 500 mV 300 mV 300.00 mV 300.00 mV 1000 mV 1000 mV 1000.0 mV 1000.0 mV Agilent U1251A/U1252A User’s and Service Guide...
  • Page 150 10 M 10.000 M 10.000 M 3.0000 M 3.0000 M 500 k 300 k 300.00 k 300.00 k 50 k 30 k 30.000 k 30.000 k 3.0000 k 3.0000 k 300.00 300.00 Agilent U1251A/U1252A User’s and Service Guide...
  • Page 151 0000.0 ºC TEMP mode Turn the rotary swich to the OPEN Input terminal oPEn oPEn A position open (Remove any test leads and Short Plugs from the input terminal) 300.00 300.00 5000 3000 3000.0 3000.0 Agilent U1251A/U1252A User’s and Service Guide...
  • Page 152 0.3 A, 1 kHz 0.3000 A 0.3000 A A mode 3 A, 1 kHz 3.0000 A 3.0000 A 10 A 3 A, 1 kHz 3.0000 A 3.0000 A 10 A, 1 kHz 10.000 A 10.000 A Agilent U1251A/U1252A User’s and Service Guide...

  • Page 153: Finishing The Adjustment

    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. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 154: Calibration Errors

    Calibration error: secure code invalid Calibration error: serial number code invalid Calibration error: calibration aborted Calibration error: value out of range Calibration error: signal measurement out of range Calibration error: frequency out of range EEPROM write failure Agilent U1251A/U1252A User’s and Service Guide...

  • Page 155: Specifications

    Agilent U1251A and U1252A Handheld Digital Multimeter User’s and Service Guide Specifications DC Specifications U1251A AC Specifications U1252A AC Specifications U1252A AC+DC Specifications Temperature and Capacitance Specifications U1251A & U1252A Frequency Specifications(1) Operating Specifications General Specifications This chapter describes the handheld digital multimeter’s specifications.
  • Page 156 Specifications Agilent U1251A/U1252A User’s and Service Guide...
  • Page 157 Specifications These specifications apply when using the U1251A and U1252A handheld digital multimeter in an environment that is free of electromagnetic interference and electrostatic charge. When using the multimeter in an environment where electromagnetic interference or significant electrostatic charge is present, measurement accuracy may be reduced.

  • Page 158: Dc Specifications

    440.00 mA 0.01 mA 0.2+5 0.15+5 0.2 V (0.01 Ω) 5.0000 A 0.0001 A 0.3+10 0.3+10 0.4 V (0.01 Ω) 0.001 A 0.3+10 0.3+5 10.000 A Diode Test 0.1 mV 1.04 mA 0.05 + 5 Agilent U1251A/U1252A User’s and Service Guide...
  • Page 159 10 MΩ (nominal) in parallel with 1.1 MΩ at dual display. [2] The accuracy could be 0.05 %+10 for U1251A and 0.05 %+5 for U1252A. Always use NULL function to zero out the thermal effect before measuring the signal.

  • Page 160: U1251A Ac Specifications

    Specifications U1251A AC Specifications Table 6 U1251A AC Accuracy ± (% of reading + No. of Least Significant Digit) Frequency Function Range Resolution 30 Hz to 45 Hz 45 Hz to 1 kHz 1 kHz to 10 kHz 10 kHz to 30 kHz True RMS 50.000 mV...

  • Page 161: U1252A Ac Specifications

    10 A to 20 A for 30 seconds maximum. After measuring a current of >10 A, leave the meter to cool down for twice the measuring time used before application of low current measurement. [6] Input current < 3 Arms. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 162: U1252A Ac+Dc Specifications

    10 A to 20 A for 30 seconds maximum. After measuring a current of >10 A, leave the meter to cool down for twice the measuring time used before application of low current measurement. [6] Input current < 3 Arms. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 163: Temperature And Capacitance Specifications

    If both calibrator and meter are set with internal reference (with internal ambient compensation), deviation may show between the readings of the calibrator and meter, due to differences in ambient compensation between calibrator and meter. [2] Only available in U1252A. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 164: U1251A & U1252A Frequency Specifications(1)

    <600 kHz 9.9999 kHz 0.0001 kHz 99.999 kHz 0.001 kHz 999.99 kHz 0.01 kHz U1251A Frequency Sensitivity During Voltage Measurement Input Range Trigger Level For DC Coupling Minimum Sensitivity (R.M.S. Sine-Wave) (Maximum input for specified 20 Hz – 100 kHz <...
  • Page 165 Specifications U1251A & U1252A Frequency Sensitivity During Current Measurement Input Range Minimum Sensitivity (R.M.S. Sine-Wave) 20 Hz – 20 kHz 500.00 μA 100 μA 5000.0 μA 250 μA 50.000 mA 10 mA 440.00 mA 25 mA 5.0000 A 10.000 A 2.5 A...
  • Page 166 Else, the accuracy and range will be different from the definition. [3] For signal frequencies greater than 1 kHz, an addition of 0.1% per kHz is added to the accuracy. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 167: Operating Specifications

    Times/second ACV + dB AC + DC V Ω/nS Diode 4 (< 100 μF) Capacitance AC + DC I Temperature Frequency 2 (>10 Hz) Duty cycle 1 (>10 Hz) Pulse width 1 (>10 Hz) Agilent U1251A/U1252A User’s and Service Guide...

  • Page 168: General Specifications

    Both primary and secondary displays are 5-digit liquid crystal display (LCD) with maximum reading of 50,000 counts. Automatic polarity indication. Power Consumption • 105 mVA / 420 mVA (with backlit) maximum (U1251A) • 165 mVA / 480 mVA (with backlit) maximum (U1252A) Operating Environment Full accuracy at –20 °C to 55 °C...

This manual is also suitable for:

U1252a

Table of Contents