Tenma 72-8720 Operating Manual Download

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Model 72-8720

OPERATING MANUAL

Model 72-8720: OPERATING MANUAL

Summary of Contents for 72-8720

Page 1: ...Model 72 8720 OPERATING MANUAL Model 72 8720 OPERATING MANUAL ...

Page 2: ... Safe Operation International Electrical Symbols 2 Getting Acquainted Turning the Meter On Battery Considerations Automatic Power Off Automatic Backlight Off Low Battery Indication The Meter Structure Rotary Switch Functional Buttons The Meter Functions Vs Displays Selecting the Range Understanding the Display Analogue Bar Graph Using MAX MIN 3 Making Measurements A Measuring DC Voltage B Measurin...

Page 3: ...ntinuity G Testing Diodes H Measuring Capacitance I Measuring Frequency Duty Cycle J Measuring Temperature K 4 20mA loop current as readout 4 Using Stores Recall and Send Features Introduction Storing and Clearing Readings Recalling Stored Readings Using Send 5 Changing the Default Setting Introduction Selecting Setup Options Saving Setup Options 6 Maintenance A General Service B Replacing the Fus...

Page 4: ...G MANUAL 7 Specifications Safety and Compliances Physical Specifications General Specifications Feature Summary Basic Specifications Detailed Accuracy Specifications A DC Voltage B AC Voltage C DC Current D AC Current E Resistance F Continuity Test G H I Frequency J Duty Cycle K Temperature 1 1 Degrees Celsius 1 2 Fahrenheit L 4 20mA loop current ...

Page 5: ...e Page List of Tables Model 72 8720 OPERATING MANUAL 1 1 Unpacking Inspection 1 2 International Electrical Symbols 2 1 Rotary Switch Selections 2 2 Functional Buttons 2 3 Functions Vs Displays 2 4 Display Features 5 1 Setup Selections ...

Page 6: ...tage Measurement 3 4 DCµA Currents Measurement 3 5 ACµA Currents Measurement 3 6 DCmA Currents Measurement 3 7 ACmA Currents Measurement 3 8 DCA Currents Measurement 3 9 ACA Currents Measurement 3 10 Resistance Measurement 3 11 Continuity Test 3 12 Diode Test 3 13 Capacitance Measurement 3 14 Frequency Duty Cycle Measurement 3 15 Temperature Measurement 3 16 4 20mA loop current as readout 6 1 Fuse...

Page 7: ...igital Multimeter 72 8720 hereafter referred to as the Meter is a 40000 counts and 4 3 4 digits with steady operations fashionable structure and auto ranging instrument It not only can measure AC voltage and current DC voltage and current Resistance Capacitance Temperature Frequency Diodes Continuity 4 20mA Loop Max Min Relative Mode but also has Setup Data Store Data Recall AC True RMS or AC DC V...

Page 8: ...aler immediately 1 2 3 4 5 6 7 8 9 10 English Operating Manual Test Lead K Type nickel chromium nickel silicon Point Contact Temperature Probe It is only suitable for measuring temperature under 230 o C Alligator Clip Test Clip USB interface cable RS232C interface cable CD ROM Installation Guide Computer Interface Software 1 5V Battery R14 AC220V 50Hz Power Cable 1 piece 1 pair 1 piece 1 piece 1 p...

Page 9: ...ards to the user or may damage the Meter or the equipment under test A Note identifies the information that user should pay attention to Rules For Safe Operation Warning To avoid possible electric shock or personal injury and to avoid possible damage to the Meter or to the equipment under test adhere to the following rules Before using the Meter inspect the case Do not use the Meter if it is damag...

Page 10: ...e inflammable and strong magnetic field The performance of the Meter may deteriorate after dampened l l l l l l When using the test leads keep your fingers behind the finger guards Disconnect circuit power and discharge all high voltage capacitors before testing resistance continuity and diodes Before measuring current check the Meterís fuses and turn off power to the circuit before connecting the...

Page 11: ...a long time When under battery operated situation constantly check the battery as it may leak when it has been using for some time replace the battery as soon as leaking appears A leaking battery will damage the Meter Under the influence of Radiated Radio Frequency Electromagnetic Field Conducted Radio Frequency Electromagnetic Field phenomenon the captioned model have a magnificent error in tempe...

Page 12: ...d with the rotary switch all previously activated button features are discarded The automatic power off is preset to 10 minutes From the Setup menu see Chapter 5 you could specify a time 10 minutes 20 minutes 30 minutes or OFF If you set to OFF the Meter retains on until you turn the rotary switch to OFF or the battery becomes too weak Under AC operated situation the automatic power off feature is...

Page 13: ...Low Battery Indication A constant battery icon in the middle left area of Model 72 8720 OPERATING MANUAL Warning To avoid false readings which could lead to possible electric shock or personal injury replace the battery as soon as the battery icon appears The Meter Structure The Figure 2 1 shows the Meter structure 1 LCD Display 2 Functional Buttons 3 Rotary Switch 4 Input Terminals ...

Page 14: ...unction The display may also be influenced by some of the choices made in Setup When you turn the rotary switch from one function to another a display for the new function appears Button choices made in one function do not carry over into another function Use the blue SELECT button to select any rotary switch alternate function labeled in blue letters ...

Page 15: ...entigrade temperature measurement AC or DC current measurement 400µA 4000µA AC or DC current measurement 40mA 400mA AC or DC current measurement 10A Rotary Switch Function Blue SELECT Function None None lFrequency measurements lDuty Cycle measurement lDiode test lContinuity test None Fahrenheit temperature measurement Toggle between AC or DC current Toggle between AC or DC current 4 20mA loop curr...

Page 16: ... the blue button to select any rotary switch alternate function labeled in blue letters LIGHT feature Under battery operated situation turn the display backlight on Under AC operated situation the backlight is always on cannot turn off Exit AUTO and enter MANUAL ranging In MANUAL select next input range Press EXIT to return to AUTO AUTO is default Store the current measurement value Press EXIT to ...

Page 17: ...H and LOW Press to display max min and current measurement reading Press EXIT to stop and return to current measurement mode l In Setup each press to select the digit you want to edit l In Recall press to enable SEND feature l In Store press to toggle between clearing all the stored reading or start storing reading from the current index number Press to enter relative mode the primary display show...

Page 18: ...cond on the storing interval Press EXIT to exit Hold feature Press HOLD to freeze the displayed value Press EXIT to release the display In Setup each press to increment an Option In Recall each press to recall the next stored reading In Store each press to increase a second on the storing interval Press to exit certain button functions and the Meter will return to the factory default setting Peak ...

Page 19: ...ue The tested ACµA value The tested DCmA value Function Primary Display Lower Right Secondary Display Upper Right Secondary Display No display The tested frequency value 40 00kHz 250 0kHz No display No display No display No display No display No display No display No display N A The tested frequency value 40 00kHz 100 0kHz No display Full range 4 40 400 1000 Full range 4 40 400 750 Full range 400 ...

Page 20: ...tested frequency value 40 00kHz 100 0kHz No display The tested frequency value 40 00kHz 100 0kHz The value of the corresponding index number The total number of stored value Full range 400 4000 Full range 10 Full range 10 Index number increase one Index number no 0001 no 9999 Index number no 0001 no 9999 Chapter 2 Getting Acquainted Using MAX MIN The present measurement value minus the stored valu...

Page 21: ...ly when you select a new function In auto range the Meter selects the lowest input range possible ensuring that the reading appears with the highest available resolution If AUTO is already on press RANGE to enter MANUAL ranging in the present range You can then select the next manual range each time you press RANGE Return to auto ranging by press EXIT Press RANGE when turning on the Meter the Mete...

Page 22: ...es Milli S Second Indicates negative reading The battery is low Warning To avoid false readings which could lead to possible electric shock or personal injury replace the battery as soon as the battery indicator appears Setup feature is on For DCV and DCA functions reading represents the True RMS total of AC and DC measurements Indicator for True RMS value 1 2 3 4 5 6 7 8 9 AC DC SET H mS µ o C o ...

Page 23: ... hertz MHz Megahertz 1x106 or 1 000 000 hertz V Volts The unit of voltage mV Millivolt 1x10 3 or 0 001 volts A Amperes amps The unit of current mA Milliamp 1x10 3 or 0 001 amperes µA Microamp 1x10 6 or 0 000001 amperes Farad The unit of capacitance nF Nanofarad 1x10 9 or 0 000000001 farads µF Microfarad 1x10 6 or 0 000001 farads mF Millifarad 1x10 3 or 0 001 farads 10 Ω kΩ MΩ Hz kHz MHz mV V µA mA...

Page 24: ...nge mode in which the Meter automatically selects the range with the best resolution Data output is in progress Backlight feature is on Data hold mode is active Peak hold mode is active Diode test l Frequency signal duty cycle l 4 20mA loop current as reading The input value is too large for the selected range Provides an analog indication of the present input quick response 12 13 14 15 16 17 18 1...

Page 25: ... and stores the new value Press MAX MIN to enter MAX MIN mode The sampling time is every 2 seconds The maximum reading and MAX are shown on the upper right secondary display The minimum reading and MIN are shown on the lower right secondary display The primary display shows the current measurement reading To exit MAX MIN mode press EXIT Press HOLD to stop the Meter updating reading MAX MIN mode ca...

Page 26: ...asured 4 The measured value shows on the display It displays the RMS Introduction Chapter 3 explains how to make measurements Most measurement functions can be selected by using the rotary switch A Measuring DC Voltage Warning To avoid harms to you or damages to the Meter from electric shock please do not attempt to measure voltages higher than 1000V although readings may be obtained While letters...

Page 27: ...the circuit under test and remove testing leads away from the input terminals of the Meter When measuring the Meter acts around a 10MΩ input impedance in parallel with the circuit This loading effect can cause measurement errors in high impedance circuits In most cases the error l l l high impedance circuits In most cases the error is negligible 0 1 or less if the circuit impedance is 10kΩ or less...

Page 28: ...rror is negligible 0 1 or less if the circuit impedance is 10kΩ or less Special care should be taken when measuring high voltage When voltage measurement has been completed disconnect the connection between the testing leads and the circuit under test and remove testing leads away from the input terminals of the Meter l l l 1 Insert the red test lead into the V terminal and the black test lead int...

Page 29: ...the black test lead into the COM terminal 2 Set the rotary switch to Press the SELECT button cycles among frequency and duty cycle 3 Connect the test leads across with the object being measured The measured value shows on the display It displays the RMS When measuring DC Millivoltage the Meter acts around a 2 5GΩ input impedance in parallel with the circuit Special care should be taken when measur...

Page 30: ...range for the measurement Never place the testing leads in parallel with any circuit or component when the leads are plugged into the current terminals To measure DCµA current set up the Meter as Figure 3 4 and proceed as follows 1 Insert the red test lead into the µAmA terminal and black test lead into the COM terminal 2 Set the rotary switch to µA DC measurement is default or press SELECT button...

Page 31: ...nt is default press SELECT button to select AC measurement mode 3 Connect the test leads in serial with the object being measured The measured value shows on the display It displays the True RMS value 4 When a ACV function is selected you can press the AC DC button to view the AC DC True RMS value in the primary display To exit please EXIT button Figure 3 5 ACµA Currents Measurement Model 72 8720 ...

Page 32: ...ack test lead into the COM terminal 2 Set the rotary switch to mA DC measurement is default or press SELECT button to select DC measurement mode 3 Connect the test leads in serial with the object being measured The measured value shows on the display It displays the RMS Figure 3 6 DCmA Currents Measurement Model 72 8720 OPERATING MANUAL ...

Page 33: ...nt is default press SELECT button to select AC measurement mode 3 Connect the test leads in serial with the object being measured The measured value shows on the display It displays the True RMS value 4 When a ACV function is selected you can press the AC DC button to view the AC DC True RMS value in the primary display To exit please EXIT button Figure 3 7 ACmA Currents Measurement Model 72 8720 ...

Page 34: ...ack test lead into the COM terminal 2 Set the rotary switch to A DC measurement is default or press SELECT button to select DC measurement mode 3 Connect the test leads in serial with the object being measured The measured value shows on the display It displays the RMS Figure 3 8 DCA Currents Measurement Model 72 8720 OPERATING MANUAL ...

Page 35: ... is allowed When the measured current is between 5A 10A continuous measurement 10 seconds and interval more than 15 minutes When current measurement has been completed disconnect the connection between the testing leads and the circuit under test and remove testing leads away from the input terminals of the Meter To measure ACA current set up the Meter as Figure 3 9 and proceed as follows 1 Insert...

Page 36: ...arge all the high voltage capacitors before measuring resistance To measure resistance set up the Meter as shown in Figure 3 10 and follow the following procedure 1 Insert the red test lead into the terminal and the black test lead into the COM terminal 2 Set the rotary switch to press SELECT button to select measurement mode 3 Connect the test leads across with the object being measured The measu...

Page 37: ... use the test lead as short as possible The LCD displays OL indicating open circuit or the tested resistor value is higher than the maximum range of the Meter When testing the resistance signal from the calibrator it is necessary to press and hold the RANGE while turning on the Meter to change the maximum display to 4000 counts but the accuracy remains unchanged When resistance measurement has bee...

Page 38: ... terminal and the black test lead into the COM terminal 2 Set the rotary switch to press SELECT button to select measurement mode and connect the test leads across with the object being tested 3 The beeper comes on continuously for open conditions that is test resistance around 50 4 The display shows the tested resistance load value The unit is The SELECT button cycles among resistance continuity ...

Page 39: ...des transistors and other semiconductor devices The diode test sends a current through the semiconductor junction then measure the voltage drop across the junction A good silicon junction drops between 0 5V and 0 8V To test the diode out of a circuit set up the Meter as Figure 3 12 and proceed as follows 1 Insert the red test lead into the terminal and the black test lead into the COM terminal 2 S...

Page 40: ...f 0 5V to 0 8V however the reverse voltage drop reading can vary depending on the resistance of other pathways between the probe tips Connect the test leads to the proper terminals as said above to avoid error display The LCD will display OL indicating either open circuit or wrong polarity connection The unit of diode is volt V displaying the positive connection voltage drop value Open circuit vol...

Page 41: ...and discharge all high voltage capacitors before measuring capacitance 1 Insert the red test lead into the terminal and the black test lead into the COM terminal 2 Set the rotary switch to measurement mode the Meter may display a fixed reading which is a internal distributed capacitor value For testing less than 10nF capacitor the tested value must subtract the3 It is recommended to use test clip ...

Page 42: ...to reduce the ef fect of internal distributed capacitor Note l l l The LCD displays OL indicating the tested capacitor is shorted or it exceeds the maximum range Capacitors larger than 400µF take longer time The analogue bar graph shows the time left before finishing the measurement When capacitance measurement has been completed disconnect the connection between the testing leads and the circuit ...

Page 43: ...rement or for duty cycle measurement The SELECT button cycles among frequency and duty cycle 3 Connect the test leads across with the object being measured The measured value shows on the primary display Note l l The requirement of Input amplitude ìaî is as follows When 10Hz 40MHz 200 mV a 30Vrms 40MHz Un specified When Hz or Duty Cycle measurement has been completed disconnect the connection betw...

Page 44: ...lay after several seconds 4 The Meter is default to Celsius o C degree unit you can change units by press the SELECT button once you have selected the temperature function Note l l l Place the Meter in an environment of 18 o C 28 o C otherwise false reading may be obtained especially in testing low temperature The included point contact temperature probe can only be used with temperature 230 o C b...

Page 45: ...n 250V from socket although readings may be obtained Before the Meter and the tested object are connected to the to be tested return circuit turn the return circuit power off It shows the mA measured value or output level in in a 4 20mA scale To use 4 20mA Loop feature connect the Meter as follows 1 Set the rotary switch to and press SELECT button to select 4 20mA feature 2 The rest procedure plea...

Page 46: ...re than 15 minutes Do not attempt to measure higher than 10A When measurement has been completed disconnect the connection between the testing leads and the circuit under test and remove the test leads away from the input terminals 3 When the readings obtained is l 4mA the primary display shows LO l 4mA the primary display shows 0 Ö l 20mA the primary display shows 100 l 20mA the primary display s...

Page 47: ...t auto update reading To change the interval in second by pressing or l l l l l l Press STORE the third time STORE and No 9999 appears The upper right secondary display shows the index number increase one The lower right secondary display shows the value of the corresponding index number the primary display shows the current measurement reading If there is no set time to store the reading each pre...

Page 48: ...data to the computer via USB or RS232 The software shows the data storing time and also the data value After the data transferring is completed the SEND feature will be disabled automatically Press or button to view additional stored reading Press and hold or to access quick recalling Press EXIT to exit recalling Recalling Stored Readings Use the following procedure to recall the stored reading Us...

Page 49: ...n this chapter Selecting Setup Options To enter the Setup mode turn the Meter on and press the SETUP button It is recommended to change the default setting only when the Meter is at DCV measurement mode In the Setup mode each press of SETUP button steps to the next Selection Each press of or button decrement or increment an Option Each Setup Selection and Option appears in the primary display in t...

Page 50: ...n off in 10 seconds Backlight turn off in 20 seconds Backlight turn off in 30 seconds Disable backlight feature It can only apply to DCV and DCI functions Selection Option Factory Default Description Max 40000 Press to select OFF Press to select the digit you want to edit Max 40000 Press to select OFF Press to select the digit you want to edit 10 20 30 OFF 1 OFF 10 20 30 OFF Zero is in the left ha...

Page 51: ...720 OPERATING MANUAL Saving Setup Options At each setup Option store your choice and exit setup by press EXIT advance to the next Option by press To exit the Setup mode without saving the present Option press Setup ...

Page 52: ...ormance test and service information A General Service l l l l l Periodically wipe the case with a damp cloth and mild detergent Do not use abrasives or solvents To clean the terminals with cotton bar with detergent as dirt or moisture in the terminals can aff fect readings Turn the Meter to OFF when it is not in use Take out the battery when it is not using for a long time Do not use or store the...

Page 53: ...ng one end loose then take out from its bracket Use the coin to open the compartment at the case top then remove the Fuse 1 and 2 by gently prying one end loose then take out from its bracket Install ONLY replacement fuses with the identical type and specification as follows and make sure the fuse is fixed firmly in the bracket Fuse 1 0 5A 250V fast type fuse ø5 20mm Fuse 2 10A 250V fast type fuse...

Page 54: ...d to possible electric shock or personal injury replace the battery as soon as the battery indicator appears when the Meter is under battery operated situation Follow Figure 6 2 and proceed as follows to replace the battery l l l l Switch off the Meter disconnect the power cord and remove all connections from the terminals Use the coin to open the compartment at the case top and separate the compa...

Page 55: ...ut terminal Fused Protection for power socket Refer to different range input protection voltage IEC 61010 CAT I 1000V CAT II 600V overvoltage and double insulation standard 0 5A 250V fast type fuse ø5 20mm 10A 250V fast type fuse ø5 20mm 0 2A 250V fast type fuse ø5 20mm Model 72 8720 OPERATING MANUAL Chapter 7 Specifications Safety and Compliances ...

Page 56: ...imes second 0 o C 40 o C 32 o F 104 o F 0 o C 40 o C 32 o F 104 o F 75 0 o C 30 o C below 50 30 o C 40 o C This Meter can be used in indoor and altitude not more than 2000M Battery Type 6pcs x 1 5V battery R14 AC 200V 240V 50Hz l In a radio field of 1 V m below Overall Accuracy Specified Accuracy 5 of Range l In a radio field of 1 V m above No assigned accuracy is specified 105 x 240 x 310 mm Appr...

Page 57: ...00 counts Left Secondary 4000 counts Right Secondary 4000 counts Bar Graph 40 segments updates 10 times second Bright backlight for clear readings in poorly lighted areas The Meter automatically selects best range Choices for AC only or AC DC readings Holds readings on display Beeper sounds for resistance readings below threshold 40 segments Measure signal on or off time in Record maximum and mini...

Page 58: ... to 1000V 100kHz bandwidth DC Voltage 0 025 AC Voltage 0 4 0 to 10A 5 10A for 10 seconds interval 15 minutes 0 to 10A 5 10A for 10 seconds interval 15 minutes 0 to 40MΩ 0 to 40mF 0 400MHz 40 o C 1000 o C 40 o F 1832 o F Up to 9999 readings may be saved by the user in a memory These readings may be viewed by using Recall feature Model 72 8720 OPERATING MANUAL Basic Specifications ...

Page 59: ... for 1 year Operating temperature 18 o C 28 o C Relative humidity 75 RH 400mV 4V 40V 400V 1000V 0 01mV 0 0001V 0 001V 0 01V 0 1V 0 025 5 under REL mode 0 05 5 0 1 8 1000V Around 2 5GΩ Around 10MΩ Model 72 8720 OPERATING MANUAL A DC Voltage Range Resolution Accuracy Overload Protection Input Impedance ...

Page 60: ... 45Hz 1kHz 1kHz 5kHz 5kHz 10kHz 0 4 30 1 5 30 6 30 0 4 30 1 5 30 6 30 0 4 30 5 30 Not Specified 1 30 5 30 10 30 0 0001V 0 001V 0 01V 0 1V Model 72 8720 OPERATING MANUAL B AC Voltage AC DC measurement is available Range Resolution Bandwidth Accuracy Remarks l Input Impedance Approx 10MΩ l Overload Protection 1000V l Display ...

Page 61: ...tinuous measurement 10 seconds and interval more than 15 minutes Model 72 8720 OPERATING MANUAL a True rms are valid from 10 of range to 100 of range b AC crest factor can be up to 3 0 except 1000V where it is 1 5 c A residual reading of 80 digits with test leads shorted will not affect stated accuracy d The accuracy guarantee range 10 100 e When making AC DC measurment the accuray need to add 1 3...

Page 62: ... residual reading of 80 digits with test leads shorted will not affect stated accuracy d The accuracy guarantee range 10 100 e When making AC DC measurement the accuracy need to add 1 35 digits of reading based on the above table l At 10A range a When the measured current is 5A continuous measurement is allowed b When the measured current is between 5A 10A continuous measurement 10 seconds and int...

Page 63: ...0 01Ω 1000V Remarks l Open circuit voltage approximate 1 2V l The buzzer does not sound when the test resistance is 50Ω l The beeper comes on continuously for open conditions that is test resistance is 10Ω Model 72 8720 OPERATING MANUAL E Resistance Range Resolution Overload Protection Accuracy Range Resolution Overload Protection F Continuity Test ...

Page 64: ...f open circuit test leads 1 20 1 2 20 5 20 Not specified 1000V 0 0001V 1000V Remarks l Open circuit voltage approximate 2 8V l A good silicon junction drops between 0 5V and 0 8V Model 72 8720 OPERATING MANUAL G Diode Test Range Resolution Overload Protection Accuracy Range Resolution Overload Protection H Capacitance ...

Page 65: ...01kHz 0 01kHz 0 0001MHz 0 001MHz 0 01MHz 0 01 8 Not Specified 1000V Remarks l Input amplitude ìaî as follows DC electric level is zero When 10Hz 40MHz 200mV a 30Vrms When 40MHz Not specified Model 72 8720 OPERATING MANUAL Range Resolution Overload Protection Accuracy I Frequency ...

Page 66: ...10Hz 40MHz 200mV a 30Vrms When 40MHz Not specified 100 0 01 40 1000V 0 01 40 o C 40 o C 40 o C 400 o C 400 o C 1000 o C 3 30 1 30 2 5 1000V 0 1 o C 65 Model 72 8720 OPERATING MANUAL J Duty Cycle Range Resolution Overload Protection Accuracy K Temperature 1 1 Degrees Celsius Range Resolution Overload Protection Accuracy ...

Page 67: ... higher than 230 o C you must use the rod contact temperature probe 4 20mA 1 50 0 01 0 5A 250V fast type fuse ø5 20mm Remarks When the readings obtained is l 4mA the primary display shows LO l 4mA the primary display shows 0 Ö 20mA the primary display shows 100 l 20mA the primary display shows HI Model 72 8720 OPERATING MANUAL 1 2 Fahrenheit Range Resolution Overload Protection Accuracy L 4 20 mA ...

Page 68: ...67 Model 72 8720 OPERATING MANUAL This operating manual is subject to change without notice END ...

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