background image

(figure 11)

Measurement Operation (9)

Note

In a circuit, a good diode should still produce a

forward voltage 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.

Connect the test leads to the proper terminals as

said above to avoid error display.

The LCD will display 

 indicating open-circuit for

wrong connection.

The unit of diode is Volt (V), displaying the positive-

connection voltage-drop value.

When diode testing has been completed, disconnect

the connection between the testing leads and the
circuit under test.

F.  DC or AC Current Measurement 

(see figure 11)

Warning

Never attempt an in-circuit current measurement
where the open-circuit voltage between the circuit
and ground is greater than 250V.
If the fuse burns out during measurement, the Meter
may be damaged or the operator himself may be
hurt. Use proper terminals, function, and range for
the measurement. When the testing leads are
connected to the current terminals, do not parallel
them across any circuit.

Select 

AC

or 

DC 

Test

black

red

A

 or

mA

Model UT70C: OPERATING MANUAL

 

24

Summary of Contents for UT70C

Page 1: ...ng and Autoranging Measurement Operation A AC Voltage Measurement B DC Voltage Measurement C DC Milivolt Measurement D Measuring Continuity Resistance Conductance Capacitance E Testing Diodes F DC or AC Current Measurement G Frequency Duty Cycle Measurement MAX MIN Recording Mode PEAK MAX MIN Mode Operation of Hold Mode Operation of Auto Hold Mode The Use of Relative Value and Relative Percentage ...

Page 2: ... Test D Capacitance E Diodes Test F DC Current G AC Current H Frequency Duty Cycle Maintenance A General Service B Testing the Fuses C Replacing the Battery D Replacing the Fuses RS232C Serial Port A RS232C Port Cable B Setting of RS232C Serial Ports C System Requirements for Installing the UT70C Interface Program Model UT70C OPERATING MANUAL 2 ...

Page 3: ...e Meter Your multimeter is an intelligent digital one a precise instrument with a resolution of 8 000 counts and up to date automatic computer calibrating function High resolution A D converter and micro controller data processing technique is adopted in the Meter featured with intelligence high precision and multi functions The Meter can be widely used in laboratory field service domestic and oth...

Page 4: ... missing or damage please contact your dealer immediately Item 1 2 3 4 5 6 7 8 Description Operating Manual Test Lead Test Clip 9V Battery NEDA1604 6F22 or 006P installed RS232C Interface Cable CD ROM Installation Guide Computer Interface Software Holster Tilt Stand Qty 1 piece 1 pair 1 pair 1 piece 1 piece 1 piece 1 piece 1 piece Model UT70C OPERATING MANUAL 4 ...

Page 5: ... a Warning identifies conditions and actions that pose hazards to the user or may damage the Meter or the equipment under test A Note identifies the information that user should pay attention on International electrical symbols used on the Meter and in this Operating Manual are explained on page 8 Model UT70C OPERATING MANUAL 5 CE Version The Meter complies with the standards IEC61010 1 in polluti...

Page 6: ...ns before using the Meter l Do not apply more than the rated voltage as marked on the Meter between the terminals or between any terminal and grounding l The rotary switch should be placed in the right position and no any changeover of range shall be made during measurement is conducted to prevent damage of the Meter l Never working at an effective voltage over 60V in DC or 30V rms in AC for there...

Page 7: ...ing the Meter case 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 altered at will to avoid damage of the Meter and any accident l Soft cloth and mild detergent should be used to clean the surface of the Meter when servicing No abrasive and solvent should be used to prevent the surfa...

Page 8: ...tional Buttons 4 Rotary Switch 5 Input Terminals AC Alternating Current DC Direct Current AC or DC Grounding Double Insulated Deficiency of Built In Battery Continuity Test Diode Capacitance Test Fuse Warning Refer to the Operating Manual Conforms to Standards of European Union Model UT70C OPERATING MANUAL 8 ...

Page 9: ...Position Function Power is turned off AC voltage measurement DC voltage measurement DC millivolt measurement Continuity test Resistance measurement Capacitance test Diode Test AC or DC Current Measurement from 0 001A to 10 00A AC or DC Current Measurement from 0 1mA to 800 0mA A mA Model UT70C OPERATING MANUAL 9 ...

Page 10: ...MAX MIN Any rotary switch position except at conductance mode Starts recording of maximum and minimum values Steps the display through the sequence of present high MAX low MIN and average AVG readings at any mode In 1ms response time it steps through only MAX and MIN reading At OFF position To select 1 second high accuracy response time press and hold down MAX MIN while turning the rotary switch t...

Page 11: ...disable the Sleep Mode press while turning on the Meter REL Any rotary switch position Press REL to enter and exit the and mode in any measuring mode the Meter beeps Hz V V mV A mA 1 Press Hz to enter frequency measurement mode the Meter beeps 2 Press Hz again to enter duty cycle measurement mode the Meter beeps 3 Press Hz again to return to the last measurement mode the Meter beeps Display Backli...

Page 12: ... indicator appears 3 Indicates negative reading 4 Test of diode 5 The continuity buzzer is on 6 The relative value mode is on which display the present value minus the stored value 7 The relative percentage value mode is on It displays the percentage value of the relative value and stored value DATA HOLD 8 Data hold is active DC AC Indicator for DC AC voltage or current The displayed value is the ...

Page 13: ...d 1 x 10 9 or 0 000000001 farads S Siemens The unit of conductance nS Nanosiemens 1 x 10 9 or 0 000000001 siemens Maximum minimum and average recording mode enabled Present reading displayed 13 100ms response time Maximum reading displayed Minimum reading displayed Average reading displayed 14 Provides an analogue indication of the present input quick response 15 Polarity indicator for the analogu...

Page 14: ...ate measurement B Manual Ranging and Autoranging The Meter has both manual range and autorange options l In the autorange mode the Meter selects the best range for the input detected This allows you to switch test points without having to reset the range l In the manual range mode you select the range This allows you to override autorange and lock the Meter in a specific range The Meter defaults t...

Page 15: ...press and hold RANGE for over one second The Meter returns to the autorange mode and is displayed Note l In Hold and MAX MIN mode press RANGE exits these measurement modes and enters manual range mode l In Hz measurement mode press RANGE to attenuate 10 times of input signal amplitude which can increase the Meter sensitivity and stabilize the correct reading Measurement Ranges 2 Model UT70C OPERAT...

Page 16: ...t lead into the COM terminal 2 Set the rotary switch to V 3 Connect the test leads across with the object being measured The measured value shows on the display which is effective value of sine wave mean value response Note l In each range the Meter has an input impedance of 10M This loading effect can cause measurement errors in high impedance circuits If the circuit impedance is less than or equ...

Page 17: ...he V Hz terminal and the black test lead into the COM terminal 2 Set the rotary switch to V 3 Connect the test leads across with the object being measured The measured value shows on the display Note l In each range the Meter has an input impedance of 10M This loading effect can cause measurement errors in high impedance circuits If the circuit impedance is less than or equal to 10k the error is n...

Page 18: ...t lead into the V Hz terminal and the black test lead into the COM terminal 2 Set the rotary switch to mV 3 Connect the test leads across with the object being measured The measured value shows on the display Note l In each range the Meter has an input impedance of 10M This loading effect can cause measurement errors in high impedance circuits If the circuit impedance is less than or equal to 10k ...

Page 19: ...60V in DC or 30V rms in AC to avoid personal dangerous Testing for Continuity see figure 6 To test for continuity connect the Meter as below 1 Insert the red test lead into the V Hz terminal and the black test lead into the COM terminal 2 Set the rotary switch to and press to select measurement mode 3 The buzzer sounds if the resistance of a circuit under test is less than 100 Note l The LCD displ...

Page 20: ...test leads across with the object being measured The measured value shows on the display Note l The test leads can add 0 1 to 0 2 of error to resistance measurement To obtain precision readings in low resistance measurement that is the range of 800 0 short circuit the input terminals beforehand using the relative value function button REL to automatically subtract the value measured when the testi...

Page 21: ...easure conductance connect the Meter as follows 1 Insert the red test lead into the V Hz terminal and the black test lead into the COM terminal 2 Set the rotary switch to and press RANGE to select nS measurement mode 3 Connect the test leads across with the object being measured The measured value shows on the display Note l It is possible to press HOLD to toggle between conductance and resistance...

Page 22: ... nF measurement mode 3 Connect the test leads or the test clips across with the object being measured The measured value shows on the display Note l For testing the capacitor with polarity connect the red test clip or red test lead to anode black test clip or black test lead to cathode instead l It takes a longer time when testing a high capacitor value the testing time is around 15 seconds in 100...

Page 23: ...nductor junction then measures the voltage drop across the junction A good silicon junction drops between 0 5V and 0 8V To test a diode out of a circuit connect the Meter as follows 1 Insert the red test lead into the V Hz terminal and the black test lead into the COM terminal 2 Set the rotary switch to 3 For forward voltage drop readings on any semiconductor component place the red test lead on t...

Page 24: ...onnection voltage drop value l When diode testing has been completed disconnect the connection between the testing leads and the circuit under test F DC or AC Current Measurement see figure 11 Warning Never attempt an in circuit current measurement where the open circuit voltage between the circuit and ground is greater than 250V If the fuse burns out during measurement the Meter may be damaged or...

Page 25: ...C current measurement mode To toggle between DC and AC current measurement function press AC current is displayed as an mean value calibrated against sine wave effective value 5 Break the current path to be tested Connect the red test lead to the more positive side of the break and the black test lead to the more negative side of the break 6 Turn on power to the circuit The measured value shows on...

Page 26: ... to display the frequency of present signal 4 Connect the test leads across with the object being measured The measured value shows on the display Note l It is recommended to use mV range which has the highest sensitivity l The attenuate amplitude of signal is different from different measuring positions and ranges therefore the required input amplitude is different when measuring frequency at dif...

Page 27: ... The measured value shows on the display Note l It is recommended to use mV range l The polarity of trigger slope is positive l The attenuate amplitude of signal is different from different measuring positions and ranges therefore the required input amplitude is different when measuring duty cycle at different measuring positions and ranges l When duty cycle measurement has been completed disconne...

Page 28: ...value In the MAX MIN mode you can also display a running average of all readings taken since the MAX MIN mode was activated Displaying the average reading allows you to smooth a rapidly changing input by displaying a stable reading on the digital display The MAX MIN mode has a pre set response time of 100ms A shorter response time captures shorter events but with decreased accuracy If you want 1 s...

Page 29: ...are erased and the Meter stays in the selected range MAX MIN Function Action To enter the MAX MIN mode 1 Make sure that the Meter is in the desired measurement function and range 2 Press MAX MIN to enter MAX MIN recording mode The present reading is displayed and the Meter is locked in the present range and REC is displayed 3 Each time a new low or high value is recorded the Meter beeps and displa...

Page 30: ...an only be enabled when the Meter is under REC mode or REC mode plus Hold mode except at mode To enter PEAK MAX MIN mode l Press MAX MIN or MAX MIN and HOLD to enter REC mode l Then press to enter PEAK MAX MIN mode 1ms response time it steps through the sequence of MAX and MIN reading ONLY Select 1ms response time black red Select MAX or MIN Model UT70C OPERATING MANUAL 30 ...

Page 31: ... Meter beeps l Press HOLD again or RANGE or turn the rotary switch to exit Hold mode the Meter beeps l In Hold mode DATA HOLD is displayed on the LCD l In conductance measurement mode press HOLD to toggle between resistance and conductance value Present resistance value is kept l The Meter displays when the selected range is overloaded l The Meter beeps when a positive result is obtained from cont...

Page 32: ...an AC DC 100mV Auto Hold mode will be enabled automatically l When the change of signal three times continuously within 3 digits it will hold the last value the Meter beeps l Considers every value as the base value When the Meter detects an input which is above the base value 300 digits the Meter beeps and holds and displays the value as the new base value Model UT70C OPERATING MANUAL 32 ...

Page 33: ...he desired measurement function before selecting REL If measurement functions change manually after REL is selected the Meter exits the REL mode l Press REL to enter mode and the present measurement range is locked and display the last measurement value as 0 as the stored value Then if carrying out measurement at this time the LCD will display the value as the result l Press REL again to enter mod...

Page 34: ... display hard to read The analogue display is divided uniformly into 10 scales and composed of 41 segments of which the full range value corresponds to the full range value of the measurement range that has been selected The polarity of the measured value is displayed as on the left of the analogue display positive polarity is not displayed For example when 80V range is selected the full range val...

Page 35: ...off if you do not turn the rotary switch or press any button for about 30 minutes The buzzer beeps three times 5 minutes before turning off l The Meter can be activated by turning the rotary switch or pressing any button If the Meter is activated by turning the rotary switch it will start from the switch selected function l To disable the Sleep Mode press while turning on the Meter l In MAX MIN mo...

Page 36: ...ond Operating 5 o C 40 o C 41 o F 104 o F Storage 10 o C 50 o C 14 o F 122 o F 80 5 o C 31 o C 50 31 o C 40 o C Operating 2000 m Storage 10000 m One piece of 9V NEDA1604 or 6F22 or 006P Display Display DATA HOLD Display Display 195 x 90 x 39 mm Approximate 550g battery included General Specifications l l 10A 250V fast type glass fuse 5x20mm CE Version IEC61010 CAT III 1000V CAT IV 600V overvoltage...

Page 37: ...0mV 8V 80V 800V 1000V 100 V 1mV 10mV 100mV 1V Overload Protection AC DC 1000V rms Remarks l Input impedance 10M l Displays effective value of sine wave mean value response l Frequency response 40Hz 400Hz B DC Voltage Range 80mV 800mV 8V 80V 800V 1000V Overload Protection AC DC 1000V rms Accuracy 0 1 3 0 1 1 Resolution 10 V 100 V 1mV 10mV 100mV 1V Remarks l At 80mV 800mV Range Input impedance 4000M...

Page 38: ...Open circuit voltage approximate 0 7V l At 800 80M Range Open circuit voltage approximate 0 7V l Conductance Test 80ns 80nS 12 5M D Capacitance Range Resolution Accuracy Overload Protection 1nF 10nF 100nF 1 F 10 F 100 F 1pF 10pF 100pF 1nF 10nF 100nF 3 5 2 3 3 5 500V rms Remark Reading under 1nF is only for reference E Diodes Test Range Diode Resolution 1mV Overload Protection 500V rms Remarks l Op...

Page 39: ...ution Accuracy Overload Protection 0 8 2 1 2 2 80mA 800mA 8A 10A 10 A 100 A 1mA 10mA Remarks l At 8A 10A Range For continuous measurement 10 seconds and interval time between 2 measurements greater than 15 minutes l Displays effective value of sine wave mean value response l Frequency response 40Hz 1kHz 1A 250V fast type glass fuse 5x20mm 10A 250V fast type glass fuse 5x20mm 10A 250V fast type gla...

Page 40: ...1Hz 0 1Hz 1Hz 10Hz 1kHz 10kHz 100kHz 1MHz Range Accuracy Overload Protection 1000V 0 1 3 10Hz 100kHz Remarks l Input amplitude 500mV rms l Maximum input amplitude 30V rms Frequency At A mA Range Remark l Input amplitude 3000 digits Duty Cycle Range Accuracy Overload Protection 0 1 3 50Hz 10kHz Range Resolution Accuracy Overload Protection 500V rms 1 5 0 01 1 99 10A 250V fast type glass fuse 5x20mm...

Page 41: ... 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 position when it is not in use and take out the battery when not using for a long time l Do not store the Meter in a place of humidity high temperature explosive inf...

Page 42: ...ngs To test the fuse 1 Set the rotary switch to and select by pressing 2 Plug a test lead into the terminal V Hz and touch the probe tip to the 10A or mA terminal l If the Meter beeps the fuse is good l If the display shows replace the fuse and test again l If the display shows any other value have the Meter serviced and contact your dealer immediately If the Meter does not work while the fuse is ...

Page 43: ...2 Take out the Meter from the holster 3 Remove the 3 rubber feet and then 3 screws from the case bottom and separate the case top from the case bottom 4 Remove the battery from the battery connector 5 Replace the battery with a new 9V battery NEDA1604 6F22 or 006P 6 Rejoin the case bottom and case top and reinstall the 3 screws and 3 rubber feet figure 15 Maintenance 3 C Replacing the Battery see ...

Page 44: ...screws fixing the PCB on the input terminals gently take apart the PCB and reverse it 5 Remove the fuse by gently prying one end loose then take out the fuse from its bracket 6 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 Fuse2 7 Rejoin the PCB and the case top and reinstall the 4 screws 8 Rejoin th...

Page 45: ... 6 7 8 2 3 4 5 6 7 8 RS232C Serial Port 1 A RS232C Port Cable The Meter Computer D sub 9PinMale D sub 9 Pin Female D sub 25 Pin Female Pin Name Remark B Setting of RS232C Serial Ports Default of RS232C serial port for communication is set as Baud Rate 9600 Start bit 1 always 0 Stop bit 1 always 1 Data bits 8 Parity Odd None Model UT70C OPERATING MANUAL 45 ...

Page 46: ... l Microsoft Windows 95 or above l At least 16 MB of RAM l At least 8MB free space in hard drive l Can access to a local or a network CD ROM l A free serial port l A mouse or other pointing device supported by Windows Please refer to the included CD ROM Installation Guide Computer Interface Software for installing and operating instructions of the UT70C Interface Program END This operating manual ...

Page 47: ...Model UT70C OPERATING MANUAL 47 ...

Page 48: ...ong Guan City Guang Dong Province China Headquarters Uni Trend International Limited Address 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 Copyright 2001 Uni Trend International Limited All rights reserved Model UT70C OPERATING MANUAL 48 ...

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