Agilent Technologies U1251A User Manual
  1. Manuals
  2. Brands
  3. Agilent Technologies Manuals
  4. Multimeter
  5. U1251A
  6. User manual

Agilent Technologies U1251A User Manual

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

Advertisement

Quick Links

See also: User Manual and Service Information , User and Service 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 Notices Warranty Safety Notices © Agilent Technologies, Inc. 2006 - 2010 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 Information

    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

    CAT III 1000 V Category IV 600 V Overvoltage Protection CAT IV 600 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 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 7 Web site. You can search the DoC by its product model or description. http://regulations.corporate.agilent.com/DoC/search.htm N O T E If you are unable to search for the respective DoC, please contact your local Agilent representative. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 8 Agilent U1251A/U1252A User’s and Service Guide...

  • Page 9: Table Of Contents

    Contents Getting Started Tutorial 13 Introducing the Agilent U1251A and U1252A Handheld Digital Multimeter Adjusting the Tilt-Stand 15 The Front Panel at a Glance 17 The Rotary Switch at a Glance The Keypad at a Glance 19 The Display at a Glance 21...
  • Page 10 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 Replacing the Battery Charging the Battery Fuse checking procedure Agilent U1251A/U1252A User’s and Service Guide...
  • Page 11 Using the Front Panel for Adjustments 143 Adjustments Consideration 144 Valid Adjustment Input Values Adjustment Procedure Finishing the Adjustment To Read the Calibration Count Calibration Errors Specifications 155 DC Specifications 156 U1251A AC Specifications U1252A AC Specifications U1252A AC+DC Specifications Agilent U1251A/U1252A User’s and Service Guide...
  • Page 12 Contents Temperature and Capacitance Specifications 161 U1251A & U1252A Frequency Specifications(1) 162 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

    (only for U1252A) • Ambient temperature on second display • Battery capacity indicator • Blue LED backlight • Resistance measurement up to 50 MΩ (for U1251A) and 500 MΩ (for U1252A) • Conductance measurement from 0.01 nS (100 GΩ) 50 nS •...

  • Page 15: Adjusting The Tilt-Stand

    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. Press subtracted from subsequent measurements. Press 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, press to switch trigger slope to positive or negative. When meter is in peak or dynamic-recording mode, press 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 the U1252A only, to set the rotary switch at square wave out position, press only the DUAL, RANGE and HOLD buttons or turn the rotary switch to another position. The LCD signs are described on pages 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 1 ms Peak Hold mode: Positive peak value on primary display 1 ms 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 See the table below. Range Counts / Segment Used for the Function V, A, Ω, Diode 2500 V, A, Ω 2500 V, A, Ω, nS 2500 V, A, Agilent U1251A/U1252A User’s and Service Guide...

  • Page 26: Selection Of Display By Hz Button

    (AC voltage) Duty cycle (%) Frequency (Hz) DC mV Pulse width (ms) (DC voltage) Duty cycle (%) Frequency (Hz) AC + DC mV Pulse width (ms) (AC + DC voltage) Duty cycle (%) [for U1252A] 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 Press to select different combinations of dual display. Normal single display resumes after you press and hold for more than 1 second. See table below. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 28 DC mV [1] Reading of dBm or dBV depends on the last review on AC V. If the last N O T E review is dBV, the following display will also remain in dBV. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 29 Hz (DC coupling) (DC current) DC A AC A Ambient temperature °C or °F DC A AC A Hz (AC coupling) AC A DC A (AC current) Ambient temperature °C or °F AC A Agilent U1251A/U1252A User’s and Service Guide...

  • Page 30: Selection Of Display By Shift Button

    DC V for U1251A DC V for U1252A AC V (AC + DC Voltage) AC + DC V for U1252A DC mV AC mV (AC + DC Voltage) AC + DC mV Ω Ω Ω Agilent U1251A/U1252A User’s and Service Guide...
  • Page 31 Square wave output for Duty cycle (%) Pulse width (ms) U1252A 1. Press to switch between dBm and dBV measurement. N O T E Press 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 2 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

    7 Connect the red and black test leads to the input terminals V.mV and COM respectively. 8 Alternatively, press to display frequency on secondary display. 9 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

    Measuring DC voltage 1 Set the rotary switch to 2 Connect the red and black test leads to the 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 the input terminals μA.mA and COM respectively. 3 Probe the test points in series with the circuit, and read the display. Measuring μA and mA current Figure 5 Agilent U1251A/U1252A User’s and Service Guide...

  • Page 40: Scale Of 4-20 Ma

    500 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 the 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 range 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 pressing Agilent U1251A/U1252A User’s and Service Guide...
  • Page 43 Making Measurements 2 Press 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 the 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 Press to scroll through audible continuity, conductance and resistance tests as shown in Figure 10. PRESS SHIFT Audible continuity PRESS SHIFT Figure 10 Audible continuity, conductance and resistance test. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 46 100 GΩ. As the high- resistance readings are susceptible to noise, you can capture the average readings by using 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

    • The diode is considered shorted if the meter displays approximately 0 V in both forward and reverse bias modes, and the meter beeps continuously. • The 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 2 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 the input terminals and COM respectively. 3 Use the red probe lead on the positive terminal of the capacitor and use the black probe lead on the negative terminal. 4 Read the display. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 52: Measuring Temperature

    The 0 °C compensation assists in measuring the relative temperature immediately. 1 Turn the rotary switch to TEMP position. 2 Press to select the temperature measurement. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 53 3 After a constant reading is obtained, press 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 2 Making Measurements 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 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 the input terminal. See Figure 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 the 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 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 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 on the display. 3 Press and hold for more than 1 second to quit this mode. Press Press Press Figure 18 Data hold mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 61: Refresh Hold

    The hold value is updated until the measuring value is stable. Then stops flashing, lights up and sounds a tone to alert the 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 a stable state for all measurements. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 63: Null (Relative)

    • When taking a DC voltage measurement, the thermal effect will influence the accuracy. Short the test leads and press 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 Press Press Press Figure 20 Null (relative) mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 65: Decibel Display

    The dBm or the dBV measurements can be selected at the ACV position. The selection will be the reference for other voltage measurements. 2 Press for more than 1 second to exit this mode. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 66 Features and Functions Press Press Press Press Press Press Press Press Press Press 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 the peak recording, press 3 Press for more than 1 second to exit this mode. 4 According to the measurements in Figure 22 on the next page, the crest Factor will be 2.5048/1.768 =1.416. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 68 Features and Functions Press Press Press Press Press Press 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 Press again to save the next value into the permanent memory. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 70 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 Press Figure 24 Full Log 3 Press 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 Press for more than 1 second to exit this mode. When interval (automatic) logging is enabled, all keypad operations are N O T E disabled, except for the LOG function. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 72 Features and Functions Press Press Press 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 Press for more than 1 second to exit mode. During the data review in either manual or interval logging mode, Press for more than one second to clear all the logged values. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 74 Features and Functions Press Press Press Press Press Press Press Press Press Press Press Press Press Press Press Press Press Press Press Figure 26 Log review mode operation Agilent U1251A/U1252A User’s and Service Guide...

  • Page 75: Square Wave Output (For U1252A)

    (ms) on the primary display. 4 Press 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 Press 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 automatically adjusts in the range of 9.9999~9999.9 ms. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 77 Features and Functions Press Press Press Press 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

    CD bundled with the meter. 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 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

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

  • Page 86: Setting Data Logging Mode

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

  • Page 87: Setting Thermocouple Types (For U1252A)

    The types of thermocouple sensor that can be selected are the J and the K types. The default type is the K type. Press to switch between the J and the K type. Press Figure 33 Thermocouple type setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 88: Setting Reference Impedance For Dbm Measurement

    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 34 Reference impedance for dBm measurement setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 89: Setting Minimum Frequency Measurement

    The typical measuring rate defined at the general specification is based on the minimum frequency of 1 Hz. Press Press Press Press Press Figure 35 Minimum frequency setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 90: Setting Temperature Unit

    • Celsius- Fahrenheit (d- CF) and Fahrenheit- Celsius (d- FC) dual display setting. Primary-Secondary Display can be swapped by pressing N O T E • Fahrenheit only (°F on primary display) single display setting. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 91 Changing The Default Setting Press Press Press Press Press 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” disables APF. is indicated on the display during subsequent measurements. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 93 Changing The Default Setting Press Press Press Press Press 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. Press 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. Press Press Press Press Press Press Figure 39 Beep frequency setup Agilent U1251A/U1252A User’s and Service Guide...

  • Page 96: Setting Backlit Timer

    • The timer can be set to 1~99 seconds. Backlit turns off automatically after the set period. • “0FF” disables turning off backlit automatically. Press Press Press Press Press 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 Select the baud rate for remote control. The available settings are 2400, 4800, 9600 and 19200 Hz. Press Press Press Press Press 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 Select the parity check for remote control. It can be set to none, even or odd bit. Press Press Press Press 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 Select the data bit for remote control. It can be set to either 8 or 7 bits. Press Figure 43 Data bit setup for remote control Agilent U1251A/U1252A User’s and Service Guide...

  • Page 100: 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 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 the Print operation. Press 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 the default factory settings except the Temperature setting. • The Reset menu item automatically reverts to Refresh Hold menu item after reset has taken place. Press 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 Replacing the Battery Charging the Battery Fuse checking procedure Replacing the Fuse Troubleshooting This chapter helps you to troubleshoot a failing handheld digital multimeter. Agilent Technologies...

  • Page 104: Introduction

    3 Wipe the case with a damp cloth and a 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: Replacing The Battery

    “Charging The Battery”. The procedures for battery replacement are listed below: 1 At the rear panel, turn the screw on the battery cover from the LOCK to the OPEN position (counterclockwise). Agilent U1251A/U1252A User’s and Service Guide...
  • Page 106 3 Lift the battery cover up. 4 Replace the specified battery. 5 Reverse the above procedures to close the cover. List of compatible batteries for the Agilent U1251A : N O T E • 9V Alkaline non-chargeable battery (ANSI/NEDA 1604A or IEC 6LR61) •...

  • Page 107: Charging The Battery

    We recommend not to charge the battery if its capacity is over 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% Agilent U1251A/U1252A User’s and Service Guide...
  • Page 108 The self- test takes about 2 to 3 minutes. Avoid pressing any button during the self- test. A message is diplayed as 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 The secondary display will count down the charging time. During charging, no buttons can be pressed. The error message may appear during charging to alert any overcharging of the battery. Figure 50 Charging mode Agilent U1251A/U1252A User’s and Service Guide...

  • Page 111: Measuring Dc Voltage

    8. Remove the DC adapter when the C–End message appears 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: Measuring Current

    Maintenance Press Figure 52 Battery charging procedures Agilent U1251A/U1252A User’s and Service Guide...

  • Page 113: Fuse Checking Procedure

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

  • Page 114: Replacing The Fuse

    3 Remove the battery cover compartment to replace the fuse. 4 Loosen the two screws on the bottom case and remove the cover. 5 Loosen the two screws on the top corners to lift the circuit board. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 115 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 53 Fuse replacement Agilent U1251A/U1252A User’s and Service Guide...

  • Page 116: Troubleshooting

    • Check that the optical side of the cable is connected to the meter and the Fail on Remote control text side of the cover is 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 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 lists the contents that are shipped along with this instrument.

  • 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 any item 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 the performance test procedures and the 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 the specifications for the next calibration interval. This criterion for the 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 54. Figure 54 LCD display Agilent U1251A/U1252A User’s and Service Guide...

  • Page 126: Current Terminal Test

    It is shown in 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 T E 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 the terminal. Figure 56 Charge terminal alert Before conducting this test, make sure the beep function is not disabled at N O T E setup. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 128: Test Considerations

    For the DC voltage, DC current, and resistance gain verification measurements, ensure that 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 between the calibrator and the multimeter. The cable shields should be earth ground referenced. This configuration is recommended to attain 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 the “Test Considerations” on page 128 before N O T E doing the performance verification tests. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 131 0.48 V, 1 kHz ± 500 mHz ± 500 mHz frequency mode Press button to go to 0.01% – 99.99% 5.0 Vpp @ ± 0.315% ± 0.315% Duty Cycle mode 50%, Square Wave, 50 Hz Agilent U1251A/U1252A User’s and Service Guide...
  • Page 132 ± 415 mV 45 V, 100 kHz ± 1.695 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 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 T E if you forget your security code. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 139: Unsecuring The Instrument For Calibration

    14 Use the editing keys to step each character in the code. Use the to select each character. 15 Press (Save) when done. 16 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) to store the new calibration security code. 6 If the new calibration security code has been successfully stored, the secondary display will show PASS. Agilent U1251A/U1252A User’s and Service Guide...
  • Page 141 7. Set the code, same as the last 4 digits of the instrument’s serial number. 8. Press (Save) to confirm the entry. 9. If the 4 digits entered are correct, the secondary display will 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 before turning off the instrument. N O T E 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 and 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

    Never turn off the instrument during an adjustment. This may delete the C A U T I O N calibration memory for the present function. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 145: Valid Adjustment Input Values

    0.9 to 1.1 x Full Scale 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 ambient compensation µ Agilent U1251A/U1252A User’s and Service Guide...

  • Page 146: Adjustment Procedure

    Always complete the tests in the same order as shown in the appropriate N O T E table. 7 Enter the actual applied input (see “Entering Adjustment Values” on page 143). Agilent U1251A/U1252A User’s and Service Guide...
  • Page 147 Repeat the adjustment procedure. 9 Repeat steps 1 through 8 for each adjustment point. 10 Verify the adjustments using the “Performance Verification Tests” on page 130. Verify the adjustments using Table 6: 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 3.0000 MW 500 kW 300 kW 300.00 kW 300.00 kW 50 kW 30 kW 30.000 kW 30.000 kW 3k W 5 kW 3.0000 kW 3.0000 kW 500 W 300 W 300.00 W 300.00 W Agilent U1251A/U1252A User’s and Service Guide...
  • Page 151 Input terminal oPEn oPEn mA position open (Remove any test leads and Short Plugs from the input terminal) 500 mA 300 mA 300.00 mA 300.00 mA 5000 mA 3000 mA 3000.0 mA 3000.0 mA 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

    Use the following procedure to read the calibration count from the front panel. 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 lists the specifications of the handheld digital multimeter.

  • Page 156: 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 157 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 the NULL function to zero out the thermal effect before measuring the signal.

  • Page 158: 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 159: U1252A Ac Specifications

    30 seconds. After measuring current >10 A, leave the meter to cool down for a period that is 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 160: U1252A Ac+Dc Specifications

    30 seconds. After measuring current >10 A, leave the meter to cool down for a period that is 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 161: Temperature And Capacitance Specifications

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

  • Page 162: 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 163 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 164 Otherwise the accuracy and the range will be different from the definition. [3] For signal frequencies greater than 1 kHz, add 0.1% per kHz to the accuracy. Agilent U1251A/U1252A User’s and Service Guide...

  • Page 165: 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 166: 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...
  • Page 167 3 months for standard accessories unless otherwise specified For the main unit, Agilent's warranty also does not cover: • Damage from contamination • Normal wear and tear of mechanical components • Manuals, fuses, or batteries Agilent U1251A/U1252A User’s and Service Guide...
  • Page 168 Specifications Agilent U1251A/U1252A User’s and Service Guide...
  • Page 169 Product specifications and descriptions in this document are subject to change without notice. Always refer to the Agilent Web site for the latest revision. © Agilent Technologies, Inc. 2006 - 2010 Printed in Malaysia Seventh Edition, November 8, 2010 U1251-90003 Agilent Technologies...

This manual is also suitable for:

U1252a

Table of Contents