UNI-T UT71C, Operating Manual

Page 1: ...Model UT71C D E OPERATING MANUAL ...

Page 2: ......

Page 3: ...tion International Electrical Symbols 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 PAGE 5 5 6 7 7 9 10 10 10 10 10 11 11 12 15 21 24 24 2 1 ...

Page 4: ...g Resistance D Testing for Continuity E Testing Diodes F Measuring Capacitance G Measuring Frequency Duty Cycle H Measuring Temperature I 4 20mA loop current as readout J Power Measurement Using Stores Recall and Send Features Introduction Storing and Clearing Readings Recalling Stored Readings Using Send PAGE 29 29 30 30 30 32 34 35 37 39 41 43 44 45 47 47 47 48 48 2 ...

Page 5: ... A General Service B Replacing the Fuses C Replacing the Battery 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 PAGE 49 49 49 52 52 53 54 55 55 56 57 58 59 60 60 61 63 64 3 ...

Page 6: ...E OPERATING MANUAL CHAPTER TITLE E Resistance F Continuity Test G Diode Test H Capacitance I Frequency J Temperature Degrees Celsius Fahrenheit K 4 20mA loop current L Power Measurement PAGE 65 65 66 66 67 68 69 69 4 ...

Page 7: ...g the Meter Low Battery Display Double Display Backlight Data Hold Automatic Power Off and full overload protection UT71E has extra Power Measurement feature Digital Multimeter UT71C D E hereafter referred to as the Meter is a 40000 counts and 4 3 4 digits with steady operations fashionable structure and auto ranging instrument They all not only can measure AC voltage and current DC voltage and cu...

Page 8: ...um nickel silicon Point Contact Temperature Probe It is only suitable for measuring temperature under 230 æ Alligator Clip model C and E only Test Clip model C and E only USB interface cable CD ROM Installation Guide Computer Interface Software Carrying Bag Power Adaptor UT71E only 9V Battery NEDA 1604 6F22 006P 1 piece 1 pair 1 piece 1 piece 1 piece 1 piece 1 piece Description Qty 1 piece 1 pair ...

Page 9: ...er and in this Operating Manual are explained on page 9 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 l Before using the Meter inspect the case Do not use the Meter if it is damaged or the case or part of the case is removed Look for cracks or missing plasti...

Page 10: ...o the circuit before connecting the Meter to the circuit l Replace the battery as soon as the battery indicator appears With a low battery the Meter might produce false readings that can lead to electric shock and personal injury l When servicing the Meter use only the same model number or identical electrical specifications replacement parts l The internal circuit of the Meter shall not be altere...

Page 11: ...d on the Meter and in this manual are explained in Table1 2 Table 1 2 International Electrical Symbols AC or DC DC Measurement AC Measurement Grounding Double Insulated Warning Refer to the Operating Manual Deficiency of Built In Battery Conforms to Standards of European Union 9 ...

Page 12: ...klight level low or high In Setup menu see Chapter 5 you could specify a time to automatically turn off the backlight 10 seconds 20 seconds 30 seconds or OFF If the period is set to OFF the backlight feature is disabled Battery Considerations The Meter uses one 9V Battery NEDA 1604 6F22 006P The following paragraphs describe several techniques used to conserve battery power Automatic Power Off The...

Page 13: ...eries are low and should be replaced 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 2 3 4 LCD Display Functional Buttons Rotary Switch Input Terminals Figure 2 1 Meter Structure 11 ...

Page 14: ...also be influenced by some of the choices made in Setup Use the blue button to select any rotary switch alternate function labeled in blue letters 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 The Table 2 1 described each rotary switch position 12 ...

Page 15: ...ty cycle measurement None l Diode test l Continuity test W UT71E only Power measurement Capacitance measurement ºC ºF UT71C D only Centigrade temperature measurement None None Fahrenheit temperature measurement Resistance measurement Blue Key Function UT71C D only DC voltage measurement UT71C D only AC voltage measurement UT71E only Hz mV UT71C D only DC voltage measurement DC millivoltage measure...

Page 16: ...y Function l Fahrenheit temperature measurement l Frequency measurement l Frequency signal duty cycle measurement AC or DC current measurement 400µA 4000µA Toggle between AC or DC current AC or DC current measurement 40mA 400mA Toggle between AC or DC current 4 20mA loop current as reading AC or DC current measurement 10A Toggle between AC or DC current 14 ...

Page 17: ...ton e g RECALL press and hold the button for over 1 second to access this additional feature This additional feature appears right above or on the left hand side of the appropriate keys To access the second additional feature of the button e g press once the button again while the Meter has already entered the first additional feature e g RECALL The second additional feature appears on the right h...

Page 18: ...nce signal from calibrator it is necessary to press this button to change the maximum display to 4000 counts but the accuracy remains unchanged Setup feature Access Setup selections the display shows SET In the Setup mode each press of SETUP button steps to the next Selection Store feature Store the current measurement value Press EXIT to exit the Store feature Press the button once Press and hold...

Page 19: ...eature Press HOLD to freeze the displayed value Press EXIT to release the display Peak Hold feature shows PEAK HOLD Press EXIT to exit l In Setup each press to select the digit you want to edit Press the button once after entering 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 Setup ...

Page 20: ...ressing second this button After exiting the light feature it is necessary to press and hold the button for over 1 second to turn the backlight on again SEND Press to display max min and average values Press EXIT to stop and return to current measurement mode Press the button once MAXMIN Press to output the data AUTO mode switch off The primary Press and hold display shows SEND Press EXIT to exit ...

Page 21: ...he button once REL The left secondary display shows the present measurement value The right secondary display shows the stored value The primary display shows the present measurement value minus the stored value Press EXIT to exit relative mode 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 i...

Page 22: ...left secondary display AC DC Use the blue button to select any rotary switch alternate function labeled in blue letters Blue Button Press and hold the Button while turning on the Meter to toggle to 4000 counts for all functions It is faster when the Meter is at 4000 counts measurement mode After the Meter is resuming from Automatic Power Off or turn on and off again the Meter will back to normal m...

Page 23: ...e Hz ºC ºF DCµA The tested frequency value The tested capacitance value The tested ºC value The tested ºF value The tested DCµA value 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 Full range 400 Full range 400 4 40 400 4 40 Full range value 400 Full range 4 Full range 40 40...

Page 24: ...ent reading Right Secondary Display The tested frequency value 40 00kHz 100 0kHz No display The tested frequency value 40 00kHz 100 0kHz No display The tested frequency value 40 00kHz 100 0kHz Apparent power value The value of the corresponding index number Power factor value Index number increase one Index number no 0001 no 0100 For UT71C UT71E no 0001 no 9999 For UT71D Full range 10 Full range 1...

Page 25: ...ue Right Secondary Display The total number of stored value Left Secondary Display Index number no 0001 no 0100 For UT71C UT71E no 0001 no 9999 For UT71D MAX MIN REL Chapter 2 Getting Acquainted Using MAX MIN The present measurement value The stored value minus the stored value The present measurement value 23 ...

Page 26: ...west 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 autoranging by press EXIT Note that there is no MANUAL ranging on REL feature Understanding the Display Display features are shown in Figure 2 2 ...

Page 27: ...reading displayed The sequence of the reading Degrees Celsius default or Fahrenheit H Hour µ Micro m Minutes Milli S Second 5 6 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 7 SET Setup feature is on Meaning 25 ...

Page 28: ...unit of resistance k Kilohm 1 x 103 or 1000 ohms M Megaohm 1 x 106 or 1 000 000 ohms Hz Hertz The unit of frequency in cycles second kHz Kilohertz 1 x 103 or 1000 hertz MHz Megahertz 1 x 106 or 1 000 000 hertz mV V µA mA A V Volts The unit of voltage mV Millivolt 1 x 10 3 or 0 001 volts A Amperes amps The unit of current mA Milliamp 1 x 10 3 or 0 001 amperes µA Microamp 1 x 10 6 or 0 000001 ampere...

Page 29: ...farads 11 12 13 14 15 16 17 LOW HIGH AUTO SEND STO RCL Automatic power off feature is on Continuity test Data store is on Data recall is on The relative mode is on to display the present value minus the stored value The indicator for the lowest setup limit The indicator for the highest setup limit The Meter is in the auto range mode in which the Meter automatically selects the range with the best ...

Page 30: ...e 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 Indicator of power factor Indicator of apparent power unit Indicator of power measurement Analogue Bar Graph Provides an analog indication of the present input quick response COS VA W Meaning 28 ...

Page 31: ...o exit MAX MIN mode press EXIT Using MAX MIN The MAX MIN mode stores minimum MIN and maximum MAX input values When the input goes below the stored minimum value or above the stored maximum value the Meter beeps 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 left secondary display The minimum reading and...

Page 32: ...rimary functions blue letters or symbols identify alternative functions Press the BLUE button to access these alternate functions A Measuring Voltages 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 To measure voltages set up the Meter as Figure 3 1 and do the following Figure 3 ...

Page 33: ...When a ACV function is selected you can press the Yellow Button to view the AC DC True RMS value in the primary display To exit please EXIT button The BLUE button cycles among mV duty cycle frequency and Note l When measuring voltage the Meter acts around a 10M V and V or 2 5G mV impedance in parallel with the circuit This loading effect can cause measurement errors in high impedance circuits In m...

Page 34: ... the Meter or to the equipment under test check the Meter s fuses before measuring current Use proper terminals function and 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 AC or DC current set up the Meter as Figure 3 2 and proceed as follows Figure 3 2 Currents Measurement 32 ...

Page 35: ...display AC measurement displays the True RMS value DC measurement displays the effective value of sine wave mean value response 7 Turn off power to the circuit and discharge all high voltage capacitors Remove the Meter and restore the circuit to normal operation When a ACA function is selected you can press the Yellow Button to view the AC DC True RMS value in the primary display To exit please EX...

Page 36: ...tors before measuring resistance To measure resistance set up the Meter as shown in Figure 3 3 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 BLUE button to select measurement mode 3 Connect the test leads across with the object being measured The measured value shows on the display The ...

Page 37: ...unts but the accuracy remains unchanged l When resistance 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 D Testing for Continuity Warning To avoid harms to you please do not attempt to input voltage higher than 60V DC or 30V rms AC To avoid possible damages to the Meter or to the d...

Page 38: ...ge around 1 2V and range is 400 measurement range l When continuity testing 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 Figure 3 4 Continuity Test 36 ...

Page 39: ...iode test to check diodes transistors and other semiconductor devices The diode test sends a current through the semicondutor 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 5 and proceed as follows 1 Insert the red test lead into the terminal and the black test lead into ...

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

Page 41: ...To avoid damage to the Meter or to the equipment under test disconnect circuit power and discharge all high voltage capacitors before measuring capacitance Use the DC Voltage function to confirm that the capacitor is discharged To measure capacitance set up the Meter as shown in Figure 3 6 and proceed as follows 1 Insert the red test lead into theterminal and the black test lead into the COM termi...

Page 42: ...en to subtract the residual capacitance of the Meter and leads 3 It is recommended to use test clip to carry out measurement to reduce the effect of internal distributed capacitor Note l The LCD displays OL indicating the tested capacitor is shorted or it exceeds the maximum range l Capacitors larger than 400µF take longer time The analogue bar graph shows the time left before finishing the measur...

Page 43: ...lead into the Hz terminal and the black test lead into the COM terminal 2 Set the rotary switch to UT71C D or ºC ºF UT71E and press BLUE button to select the Hz measurement mode for frequency measurement or for duty cycle measurement The BLUE button cycles among mV frequency and duty cycle for UT71C and UT71E 3 Connect the test leads across with the object being measured The measured value shows o...

Page 44: ... Input amplitude a is as follows When 10Hz 40MHz 200 mVa30Vrms 40MHz Un specified l When Hz 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 42 ...

Page 45: ...tch to ºC ºF the display shows OL Short circuit the test leads to show the room temperature The Meter is default to Celsius ºC degree unit you can change units by press the BLUE button once you have selected the temperature function 2 Insert the point contact temperature probe into the Meter as figure 10 3 Place the temperature probe to the object being measured The measured value shows on the dis...

Page 46: ...e socket and remove the multi purpose socket away from the Meter 2 The rest procedure please follow B Measuring Current DC current measurement Figure 3 2 3 When the readings obtained is l 4mA the primary display shows LO l l4mA the primary display shows 0 20mA the primary display shows 100 l 20mA the primary display shows HI I 4 20 mA loop current as readout It shows the mA measured value or outpu...

Page 47: ...measured connect to the circuit To measure power proceed the following 1 Set the rotary switch to W 2 Insert the power adaptor to the corresponding input terminals and plug the power adaptor to the outlet 3 Insert the object to be measured into the outlet of the power adaptor 4 The measured value shows on the display The primary display shows the power value the left secondary display show the pow...

Page 48: ...nuous measurement is allowed l 5A 10A only 10 seconds continuous measurement is allowed and the interval between each measurement must be greater than 15 minutes When power measurement has been completed first switch off the power then disconnect the connection between the adaptor and the outlet 46 ...

Page 49: ...y shows the storing time interval in second it is preset to zero To change the interval in second by pressing or button The interval can l l be as high as 255 seconds or as low as 0 second Press and hold STORE to access the quick setting Press STORE the third time STO and no appears The left secondary display shows the index number increase one The right secondary display shows the value of the co...

Page 50: ... secondary display shows the total number of the stored data l Press button to enable the SEND feature to export the data to the computer via USB 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 l Press or button to view additional stored reading Press and hold RECALL to access quick recalling ...

Page 51: ...the procedure described in this chapter Each Setup Selection and Option appears in the primary display in the sequence shown in Table 5 1 Selecting Setup Options To enter the Setup mode turn the Meter on and press and hold SETUP button for over 1 second 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 ...

Page 52: ...ion Over the upper limits beeps not continuously Over the lower limits beeps not continuously 10 mins power off 20 mins power off 30 mins power off Power off feature is disabled Beeps continuously and icon lights on No beep icon flashes Backlight turn off in 10 seconds Backlight turn off in 20 seconds Backlight turn off in 30 seconds Disable backlight feature to select the digit you want to edit t...

Page 53: ...n only apply to DCV DCI and C F functions Description Analogue Zero is in the left hand side Bar Graph Zero is in the center 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 51 ...

Page 54: ...nce test and service information A General Service l Periodically wipe the case with a damp cloth and mild detergent Do not use abrasives or solvents l To clean the terminals with cotton bar with detergent as dirt or moisture in the terminals can affect readings l Turn the Meter to OFF when it is not in use l Take out the battery when it is not using for a long time l Do not use or store the Meter...

Page 55: ...erminals l Remove the 5 screws from the case bottom l Remove the fuse by gently prying one end loose then take out the fuse from its bracket l 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 5 20mm Fuse 2 10A 250V fast type fuse 5 20mm l Rejoin the case bottom and case top and ...

Page 56: ...d from the circuit being tested before opening the case bottom Follow Figure 6 2 and proceed as follows to replace the battery l Turn the rotary switch to OFF and remove all connections from the terminals l Remove the screw from the battery compartment and separate the battery compartment from the case bottom l Replace with a new 6F22 9V battery l Rejoin the case bottom and battery compartment and...

Page 57: ...al and Grounding Refer to different range input protection voltage Certification Compliances Fused Protection for µAmA input terminal Fused Protection for A input terminal IEC 61010 CAT III 1000V CAT IV 600V overvoltage and double insulation standard 0 5A 250V fast type fuse 10A 250V fast type fuse 5 20mm 5 20mm 55 ...

Page 58: ...ng Temperature Storage Temperature Relative Humidity Battery Type Electromagnetic Compatibility 0ºC 40ºC 32ºF 104ºF 10ºC 50ºC 14ºF 122ºF 75 0ºC 30ºCæ below 50 30ºC 40ºC 9V NEDA 1604 or 6F22 or 006P 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 Dimensions H x W x L Weight 177 x 85 x 40mm Approx 34...

Page 59: ...Model UT71C D E OPERATING MANUAL General Specifications Range Polarity Overloading Battery Deficiency Auto Auto Display OL except at 4 20mA Loop range which display HI or LO Display 57 ...

Page 60: ...tness levels Autorange AC DC True RMS AC RMS Data Hold Continuity Bar Graph Duty Cycle MAX MIN Mode Battery Access Door 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...

Page 61: ... 0 to 1000V 0 to 1000V 100kHz bandwidth DC Voltage 0 025 AC Voltage 0 4 0 to 10A 5 10A for 0 to 10A 5 10A for 0 to 40M 0 to 40mF 0 400MHz 40ºC 1000ºC 40ºF 1832ºF Up to 100 readings for UT71C and UT71E or 9999 readings for UT71D may be saved by the user in a memory These readings may be viewed by using Recall feature 10 seconds interval 15 minutes 10 seconds interval 15 minutes Ranges Description 5...

Page 62: ...er of least significant digits guarantee for 1 year Operating temperature 18ºC 28ºC Relative humidity 75 RH A DC Voltage Range 400mV 4V 40V 400V 1000V Resolution 0 01mV 0 0001V 0 001V 0 01V 0 1V 0 1 8 0 05 5 1000V Around 10M Accuracy 0 025 5 Overload Protection Input Impedance Around 2 5G 60 ...

Page 63: ... Resolution 0 0001V Bandwidth 45Hz 1kHz 1kHz 10kHz 10kHz 100kHz 40V 0 001V 45Hz 1kHz 1kHz 10kHz 10kHz 100kHz 400V 0 01V 45Hz 1kHz 1kHz 10kHz 10kHz 100kHz 1000V 0 1V 45Hz 1kHz 1kHz 5kHz 5kHz 10kHz Accuracy 0 4 30 1 5 30 6 30 0 4 30 1 5 30 6 30 0 4 30 5 40 Not Specified 1 30 5 30 10 30 61 ...

Page 64: ...o 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 When frequency is lower than 100kHz the accuracy guarantee range 10 100 e When making AC DC measurment the accuray need to add 1 35 digits of reading based on the above table 62 ...

Page 65: ...01A 0 5 30 10A 250V fast type fuse 5 20mm 0 15 15 Accuracy 0 1 15 0 5A 250V fast type fuse 5 20mm Overload Protection Remarks At 10A range l When the measured current is 5A continuous measurement is allowed l When the measured current is between 5A 10A continuous measurement 10 seconds and interval more than 15 minutes 63 ...

Page 66: ...e rms are valid from 10 of range to 100 of range b AC crest factor can be up to 3 0 c A residual reading of 80 digits with test leads shorted will not affect stated accuracy d When frequency is lower than 100kHz the accuracy guarantee range 10 100 e When making AC DC measurment the accuray need to add 1 35 digits of reading based on the above table l At 10A range a When the measured current is 5A ...

Page 67: ... test leads open circuit value 0 3 8 1000V 0 5 20 1 40 1 5 40 Overload Protection F Continuity Test Range Resolution 0 01 Overload Protection 1000V Remarks l Open circuit voltage approximate 1 2V l The buzzer does not sound when the test resistance is 60 l The beeper comes on continuously for open conditions that is test resistance is 40 65 ...

Page 68: ...l A good silicon junction drops between 0 5V and 0 8V Overload Protection 1000V H Capacitance Range 40nF 400nF 4µF 40µF 400µF 4mF 40mF Resolution 0 001nF 0 01nF 0 0001µF 0 001µF 0 01µF 0 0001mF 0 001 mF 1 2 20 5 20 Not specified 1 20 1000V Accuracy 1 20 capacitance value of open circuit test leads Overload Protection 66 ...

Page 69: ...z 4MHz 40MHz 400MHz Resolution 0 001Hz 0 01Hz 0 0001kHz 0 001kHz 0 01kHz 0 0001MHz 0 001MHz 0 01MHz Not Specified 0 01 8 1000V Accuracy Overload Protection Remarks l Input amplitude a as follows DC electric level is zero When 10Hz 40MHz 200mV a 30Vrms When 40MHz Not specified 67 ...

Page 70: ...ion Fahrenheit Range 40ºF 32ºF 32ºF 752ºF 752ºF 1832ºF 0 1ºF Resolution Accuracy 4 50 1 5 50 3 1000V Overload Protection Remarks l Included is a K Type nickel chromium nickel silicon point contact temperature probe which could only measure temperature below 230ºC If you want to measure temperature higher than 230ºC you must use the rod contact temperature probe 68 ...

Page 71: ...display shows LO l 4mA the primary display shows 0 20mA the primary display shows 100 l 20mA the primary display shows HI L Power Measurement UT71E only Range 2500W Resolution 0 1W Accuracy 2 50 Current Overload Protection 10A 250V fast type fuse 5 20mm Voltage Overload Protection 1000V Remarks l Power factor input range 0 00 1 00 l Voltage input impedance around 10M l Voltage input range AC50 250...

Page 72: ...i Trend Technology Dongguan Limited Dong Fang Da Dao Bei Shan Dong Fang Industrial Development District Hu Men Town Dongguan City Guang Dong Province China Postal Code 523 925 Headquarters Uni Trend Group Limited Rm901 9 F Nanyang Plaza 57 Hung To Road Kwun Tong Kowloon Hong Kong Tel 852 2950 9168 Fax 852 2950 9303 Email info uni trend com http www uni trend com 70 ...