Introduction, General maintenance | Agilent Technologies U1251A

5 Maintenance

Introduction

	C A U T I O N	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.
		be performed by qualified personnel.

General maintenance

	WA R N I N G	Ensure that the terminal connections are correct for that particular
	WA R N I N G	measurement before proceeding. To avoid damaging the device, do not

		exceed the input limit.

Besides the above hazard, dirt, or moisture in the terminals can distort readings. The steps for cleaning are as follows:

1Turn the meter off and remove the test leads.

2Turn the meter over and shake out any dirt that may have accumulated in the terminals.

3Wipe 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.

Battery replacement

The meter is powered by a 9 V Ni- MH rechargeable battery,

7.2V nominal voltage. Use only the specified type (refer to Figure 5- 1 below).

To ensure that the correct battery type is used, replace the battery immediately when the low battery sign flashes. If your meter has the rechargeable battery type, refer to the section “Charging the battery” on page 98. The steps for battery replacement are listed below:

96	Agilent U1251A/U1252A User’s and Service Guide

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Agilent Technologies U1251A manual Introduction, General maintenance, Battery replacement

Contents

Agilent U1251A U1252A Handheld Digital Multimeter U T I O N WA R N I N G Safety Symbols Safety Information WA R N I N G Never measure voltage when current measurement is selected Meter, and follow the correct polarity Regulatory Markings Product Category Affixed product label is as shown below This Guide… Declaration of Conformity DoC Contents Setting Percentage % Scale Readout Overload alert Returning to Default Factory Settings Agilent Technologies calibration servicesAdjustment is recommended Calibration interval Adjustments Consideration Valid adjustment input valuesAdjustment procedure Calibration errors 161 III Xviii List of Figures Reset setup List of Tables 159 Getting Started Introducing the U12521A/U1252A Handheld Digital Multimeter Introducing the U12521A/U1252A Handheld Digital Multimeter Check the shipment Adjusting the tilt-stand IR-USB cable To PC host Tilt-stand at 3Tilt-stand at hanging position Display Keypad Rotary switch Terminal Connectors Front panel at a glance IR communication port Tilt-stand Battery access coverRear panel at a glance Rotary switch at a glance 7U1252A keypad 2Keypad desciption and functions Button Sets to Auto Range mode Display at a glance 3General display symbols LCD symbol Description 4Priamry display symbols 5Secondary display symbols KHz Range Counts/segments Used for the function 6Analog bar range and counts2500 Diode Ω, nS Selecting display with the Hz button 7Selecting display with the Hz button Frequency Hz Duty cycle % Frequency HzHz Frequency counter press Frequency Hz Pulse width ms Duty cycle % Hz Frequency counter press Frequency Hz 100 Selecting display with the Dual button 8Selecting display with the Dual buttonBy pressing For U1251A AC a Rotary switch position Function Primary display Selection display with the Shift buttonHz AC coupling 9Selecting display with the Shift button 9Selecting display with the Shift button For U1252A DC mV Temp Rotary switch position Input terminals Overload protection Terminals at a glance Making Measurements Understanding The Measurement Instructions No.Instructions Understanding The Measurement Instructions1Numerical steps descriptions Measuring AC voltage Red Lead Black Lead Measuring DC voltage 2Measuring DC voltage Press If necessary to ensure Measuring CurrentΜA & mA measurement Black Lead Red Lead 3Measuring μA and mA current 2Percentage scale and measurement range Percentage scale of 4 mA to 20 mAPress 4Measuring scale of 4-20 mA Ampere measurement 5A ampere current measurement Frequency Counter 6Measuring frequency Measuring Resistance, Conductance and Testing Continuity Audible continuity 8Audible continuity, conductance, and resistance test 3Audible continuity measurement range Measurement range Beeper sound threshold 9Conductance measurement Testing Diodes 10Measuring forward bias of diode 11Measuring reverse bias of diode Measuring Capacitance Means the capacitor is charging Discharging 12Capacitance measurements Measuring Temperature 14Connecting the probe with adapter into the multimeter Making Measurements 15Surface temperature measurement Input warning Alerts and Warning During MeasurementOverload alert Charge terminal alert 17Charge terminal alert Functions and Features Dynamic Recording Press to restart the dynamic recording 1Dynamic recording mode operation 2Data hold mode operation Data Hold Trigger Hold Refresh Hold Press to return Null Relative 4Null relative mode operation Decibel Display Reference for other voltage measurements 5dBm/dBV display mode operation Press Pres s Ms Peak Hold If the reading is OL, pressTo re-start the peak-recording measurement If you need to re-start the peak recording, press 61 ms peak hold mode operation Data Logging Manual logging Full Log Interval logging Are filled, Full is indicated on the secondary display 9Interval Automatic logging mode operation Reviewing logged data 10Log review mode operation Square Wave Output for U1252A Frequency Hz 11Frequency adjustment for square wave output Press 13Duty cycle adjustment for Square Wave Remote Communication Connect To PC Features and Functions Changing The Default Setting Setting Data Bit Selecting Setup Mode Display Description 1Available setting options in Setup modeMenu Item Available setting options Swaps display to C Setting Data Hold/Refresh Hold Mode 1Data hold/Refersh hold setup Setting Data Logging Mode Press PressPress Setting Thermocouple Types U1252A only 3Thermocouple type setup Setting Reference Impedance for dBm Measurement 4Reference impedance for dBm measurement setup Setting Minimum Frequency Measurement 5Minimum frequency setup Setting Temperature Unit 6Temperature unit setup Setting Auto Power Saving Mode 7Auto power saving setup Setting Percentage % Scale Readout % scale readout setup Setting Beep Frequency 9Beep frequency setup Setting Backlight Timer 10Backlit timer setup Setting Baud Rate 11Baud rate setup remote control Setting Parity Check 12Parity check setup Setting Data Bit 13Data bit setup for remote control Setting Echo Mode 14Echo mode setup for remote control Setting Print Mode 15Print mode setup for remote control Returning to Default Factory Settings Press Press Maintenance Introduction General maintenanceBattery replacement Nominal voltage List of compatible batteries for the Agilent U1251AList of of compatible batteries for the Agilent U1252A Multimeter is to be unused for long periods of time Charging the batteryStorage considerations U T I O N 2Battery capacity display as trickle Condition Battery voltage Proportional percentage 2Error messages Error Error message 4Charging mode Agilent U1251A/U1252A User’s and Service Guide 103 6Battery charging procedure Fuse checking procedure Figure above Replacing the fuse 3Measurement readings for fuse checking Fuse Agilent part number Rating Size Type 4Fuse specificationsFuse Malfunction Troubleshooting procedure Troubleshooting5Basic troubleshooting procedures Replaceable Parts To order replaceable parts 110 Agilent U1251A/U1252A User’s and Service Guide Current terminal test Closed- case electronic calibrationBacklit test Closed-case electronic calibration Agilent Technologies calibration servicesCalibration Overview Adjustment is recommended Calibration interval Application Recommended equipment Recommended Test Equipment1Recommended Test Equipment Backlit test Testing the displayBasic Operating Test Setup Current terminal test Charge terminal alert test Test Considerations Calibration Security Performance Verification Tests Doing the performance verification tests Step Test Function Range Error from nominal 1 year2Performance verification test steps U1251A ± 20 mV ± 17.5 mV 500 ± 200 mV 1000 ± 800 mV Agilent U1251A/U1252A User’s and Service Guide 123 ± 75 μV ± 350 mW 33250A Output Step Test Function Range 5520A Output Square Wave Use 53131A Output Use 34410A Agilent U1251A/U1252A User’s and Service Guide 127 Unsecuring the instrument for calibration To Unsecure the Instrument from the Front Panel Agilent U1251A/U1252A User’s and Service Guide 129 Tory default code using the front panel Calibration process Using the front panel for adjustments Selecting the Adjustment Mode Calibration memory for the present function Adjustments ConsiderationProblem and repeat the procedure Function Range Valid Amplitude Input Values Valid adjustment input values3Valid adjustment input values Adjustment procedure Simultaneously to exit the adjustment mode 136 Agilent U1251A/U1252A User’s and Service Guide 4Adjustment table Step Test Function Cal Range Input Cal Item U1251A U1252A 138 Agilent U1251A/U1252A User’s and Service Guide Agilent U1251A/U1252A User’s and Service Guide 139 Open Agilent U1251A/U1252A User’s and Service Guide 141 Your instrument was calibrated before it left the factory Finishing the adjustmentTo read the calibration count Calibration errors Number Recommended Accuracy Requirements 144 Agilent U1251A/U1252A User’s and Service Guide Frequency Sensitivity Specifications Frequency Counter Specifications for U1252A Product Characteristics Power Supply Agilent U1251A/U1252A User’s and Service Guide 147 Calibration Cycle Measurement Category Measurement category definition Specification Assumptions Electrical Specifications DC SpecificationsFunction Range Resolution Burden Voltage U1251A U1252A Accuracy Maximum open voltage + 4.2 AC Specifications Frequency Function Range Resolution Function Range Resolution 45 Hz KHz 10 kHz 20 kHz Function Range ResolutionFrequency 20 Hz 45 Hz KHz 10 kHz Frequency Hz 45 Hz Frequency 30 Hz 45 Hz KHz 7U1252A true RMS ac+dc current specificationsFunction Range Resolution 45 Hz KHz 10 kHz Capacitance Specifications Temperature Specifications8Capacitance specifications 9Temperature specifications Frequency Specifications Duty Cycle and Pulse Width Specifications10Frequency specifications 11Duty cycle and pulse width specifications Frequency Sensitivity Specifications Minimum sensitivity RMS sine waveModel Number U1251A U1252A 100 kHz Input Range Peak Hold SpecificationsSignal Width Accuracy For DC mV/voltage/current Frequency Counter Specifications for U1252A 15Frequency counter divide by 1 specifications16Frequency counter divide by 100 4 specifications Sensitivity Min. Input Frequency Output Range Accuracy 17Square wave output specificationsSquare Wave Output for U1252A Operating Specifications Display update rate approximate18Display update rate approximate Realtime clock. Only ONE sample per second can be logged Input impedance 19Input Impedance 164 Agilent U1251A/U1252A User’s and Service Guide Contact us