UNI-T VC820, Operating Manual

Page 1: ...Functional Buttons Display Symbols Manual Ranging and Autoranging Measurement Operation A DC Voltage Measurement B AC Voltage Measurement C Measuring Resistance D Testing for Continuity E Testing Diode F Capacitance Measurement G Frequency or Duty Cycle Measurement H Temperature Measurement I DC or AC Current Measurement Operation of Hold Mode The Use of Relative Value Mode POWER Button ...

Page 2: ...st E Diode Test F Capacitance G Frequency Duty Cycle H Temperature I DC Current J AC Current Maintenance A General Maintenance Service B Testing the Fuses C Replacing the Battery D Replacing the Fuses RS232C Serial Port A Connect with computer B RS232C Port Cable C Setting of RS232C Serial Ports D System Requirements for Computer Interface Software ...

Page 3: ...ional measuring functions there is a RS232C standard serial port is equipped with this Meter for easy connection with computer to realize macro recording and monitoring and capture of transient dynamic data displaying change of waveform during the measurement providing data and evidence to engineering technicians for scientific research This is also a highly applied digital multimeter of high perf...

Page 4: ...n this manual a Warning identifies conditions and actions that pose hazards to the user or may damage the Meter or the equipment under test This Meter complies with the standards GB4793 1 IEC1010 1 In pollution degree 2 overvoltage category CAT II 1000V CAT III 600V and double insulation CAT II local classification of CAT II electronic equipment portable units Its transient overvoltage shall be le...

Page 5: ...hould be disconnected from the tested circuit and the POWER should be pressed off before opening the case 8 Identical nominal fuse of quick response must be used for replacement of a broken fuse 9 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 10 The internal circuit of the Meter s...

Page 6: ...cal Symbols AC Alternating Current Deficiency of Built In Battery DC Direct Current Continuity Test AC or DC Diode Grounding Fuse Double Insulated Conforms to Standards of European Union Warning Functional Structure see figure 1 LCD Display ...

Page 7: ...ed test lead for testing current µA or mA or temperture 20A Input Terminal Insert red test lead for testing current A Rotary Switch Switch Position Function V AC or DC Voltage Measurement Ω VC820 ONLY Continuity or Diode or Resistance Test Ω VC840 ONLY Continuity or Diode or Resistance or Capacitance Test VC820 ONLY Capacitance Test Hz Frequency Measurement VC840 ONLY Temperature in Celsius µA AC ...

Page 8: ...ode the Meters beeps Manually selecting a range causes the Meter to exit the Hold and REL modes 2 Press RANGE to step through the ranges available for the selected function the Meter beeps 3 Press and hold RANGE for 2 seconds to return to autoranging the Meter beeps Hz or Hz Frequency or Duty Cycle Test a In frequency mode press Hz to toggle between frequency measurement Hz and duty cycle mode the...

Page 9: ...eter beeps HOLD H Data Holding Press HOLD to enter and exit the Hold mode in any mode Display Symbols see figure 2 Number Symbol Meaning 1 AC Indicator for AC voltage or current VC820 The displayed value is the mean value VC840 The displayed value is the true rms value 2 TRMS VC840ONLY Indicator for true rms value ...

Page 10: ...gs which could lead to possible electric shock or personal injury replace the battery as soon as the battery indicator appears 9 0 C Centigrade The unit of temperature 10 Test of diode 11 The continuity buzzer is on Ω kΩ MΩ Ω kΩ MΩ Ohm The unit of resistance kilohm 1 x 103 or 1000 ohms Megohm 1 x 106 or 1 000 000 ohms µF nF F µF nF Farad The unit of capacitance Microfarad 1 x 10 6 or 0 000001 fara...

Page 11: ...nual range and autorange options z In the autorange mode the Meter selects the best range for input signals This allows you to switch test points without having to reset the range z In the manual range mode you may select the range This allows you to override autorange and lock the Meter in a specific range The Meter defaults to the autorange mode in measurement functions that have more than one r...

Page 12: ...mode and is displayed Measurement Operation A DC Voltage Measurement Warning To avoid harms to you or damages to the Meter from electric shock please do not attempt to measure voltages higher than 1000V 750V TRMS although readings may be obtained The DC Voltage ranges are 400 0mV 4 000V 40 00V 400 0V and 1000V To measure DC Voltage connect the Meter as follows 1 Insert the red test lead into the H...

Page 13: ...rom electric shock please do not attempt to measure voltages higher than 1000V 750V TRMS although readings may be obtained The AC Voltage ranges are 400 0mV 4 000V 40 00V 400 0V and 750V To measure AC Voltage connect the Meter as follows 1 Insert the red test lead into the HzVΩterminal and the black test lead into the COM terminal 2 Set the rotary switch to V and press SELECT blue button to select...

Page 14: ...0kΩ 400 0kΩ 4 000MΩand 40 00MΩ To measure resistance connect the Meter as follows 1 Insert the red test lead into the HzVΩ terminal and the black test lead into the COM terminal 2 Set the rotary switch toΩ and press SELECT blue button to selectΩmeasurement mode 3 Connect the test leads across with the object being measured The measured value shows on the display The test leads can add 0 1Ωto 0 2Ω ...

Page 15: ...esting for Continuity Warning To avoid damages to the Meter or to the devices under test disconnect circuit power and discharge all the high voltage capacitors before testing for continuity To test for continuity connect the Meter as below 1 Insert the red test lead into the HzVΩterminal and the black test lead into the COM terminal 2 Set the rotary switch toΩ and press SELECT blue button to selec...

Page 16: ... the red test lead into the HzVΩterminal and the black test lead into the COM terminal 2 Set the rotary switch toΩ and press SELECT blue button to select measurement mode 3 Connect the test leads across with the object being measured The measured value shows on the display Connect the test leads to the proper terminals as said above to avoid error display The LCD will display OL indicating open ci...

Page 17: ...est leads or the test clips across with the object being measured The measured value shows on the display The LCD displays OL indicating the tested capacitor is short or it exceeds the maximum range For testing the capacitor with polarity connect the red clip to positive black clip to negative When capacitance measurement has been completed disconnect the connection between the testing leads and t...

Page 18: ...le mode Connect the Meter as above mentioned when carrying out duty cycle measurement The duty cycle measurement range is 0 1 99 9 The LCD displays OL indicating the inputted signal is high or low level When Hz or measurement has been completed disconnect the connection between the testing leads and the circuit under test and remove the testing leads away from the input terminals of the Meter H Te...

Page 19: ...er 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 The current measurement has 3 measurement positions on the rotary switch µA mA and A The µA has a 400 0µA and 4000µA range with auto ranging the mA has a 40 00mA and 400 0mA range with...

Page 20: ... The measured value shows on the display Effective value stability period When the reading obtained is less than 100 the effective value converter needs a longer time to become stabilize When there is no input voltage the maximum reading displayed is 10 For safety sake the measuring time for high current should be less than 10 seconds for each measurement and the interval time between 2 measuremen...

Page 21: ...measurement It subtracts a stored value from the present measurement value and displays the result For instance if the stored value is 20 0V and the present measurement value is 22 0V the reading would be 2 0V If a new measurement value is equal to the stored value then display 0 0V When REL mode is selected the Meter will switch from Autoranging to Manual ranging except under capacitance testing ...

Page 22: ...lecting the required measurement function when there is more than one function at one position of the rotary switch General Specification 1 HzVΩ Maximum voltage between terminal and ground is 1000Vrms 2 µAmA Input Terminal 0 5A 600V fast type ceramic fuse VC820 µAmA Input Terminal 0 5A 600V fast type ceramic fuse VC840 3 20A Input Terminal 20A 600V fast type ceramic fuse 4 Maximum Display 3999 upd...

Page 23: ... battery included 12 Certificate Accuracy Specification Accuracy a reading b digits guarantee for 1 year Operating temperature 23 5 Relative humidity 75 A DC Voltage Range Resolution Accuracy Input Protection Remarks 400mV 0 1mV 0 8 3 4V 1mV 40V 10mV 400V 100mV 0 8 1 1000V 1V 1 3 1000V DC 750V AC Input impedance 10MΩ B AC Voltage Range Resolution Accuracy Input Protection Remarks ...

Page 24: ...true rms value Frequency response 40 400Hz C Resistance Range Resolution Accuracy Input Protection Remarks 400Ω 0 1Ω 1 2 2 4kΩ 1Ω 40kΩ 10Ω 400kΩ 100Ω 1 2 4MΩ 1kΩ 1 2 2 40MΩ 10kΩ 1 5 2 1000Vp Open circuit voltage approx 0 45V D Continuity Test Range Resolution Accuracy Input Protection Remarks 400 0Ω 0 1Ω Approx 70Ω 1000Vp Buzzer beeps continuously Open circuit voltage approx 0 5V E Diode Test ...

Page 25: ... drop 0 5V 0 8V F Capacitance Range Resolution Accuracy Input Protection Remarks 40nF 10pF 3 10 Measure at REL mode 400nF 100pF 4µF 1nF 40µF 10nF 3 5 100µF 100nF 4 5 1000Vp G Frequency Duty Cycle Range Resolution Accuracy Input Protection Remarks 5Hz 10MHz N A 0 1 3 1000Vp Input sensitivity 1MHz 300m Vrms 1MHz 600m Vrms 0 1 99 9 0 01 Reading is only for reference purpose ...

Page 26: ...ype φ5x25mm 1 DC Current Accuracy Range Resolution VC820 VC840 Input Protection Remarks 400µA 0 1µA 4000µA 1µA 1 2 40mA 0 01mA 400mA 0 1mA 1 2 3 Ceramic Fuse 0 5A 600V 4A 0 001A 20A 0 01A 1 5 5 Ceramic Fuse 20A 600V For continuous measurement 10 seconds and interval not less than 15 minutes J AC Current Accuracy Range Resolution VC820 VC840 Input Protection Remarks ...

Page 27: ...ervice your Meter unless you are qualified to do so and have the relevant calibration performance test and service information A General Service Periodically wipe the case with a damp cloth and mild detergent Do not use abrasives or solvents z To clean the terminals with cotton bar with detergent as dirt or moisture in the terminals can affect readings z Turn off the power of the Meter when it is ...

Page 28: ...et the rotary switch toΩ and press SELECT blue button to select 2 Plug a test lead into the terminal HzVΩand connect the probe tip to the 20A terminal 3 If the Meter beeps the fuse is good z If the display shows O L overvoltage replace the fuse If the Meter does not work while the fuse is all right send it to your dealer for repair C Replacing the Battery see figure 3 ...

Page 29: ...d false readings which could lead to possible electric shock or personal injury replace the battery as soon as the battery indicator appears To replace the battery 1 Press the POWER to turn the Meter off and remove all connections from the terminals ...

Page 30: ...3 Remove the battery from the battery compartment 4 Replace the battery with a new 9V battery NEDA1604 6F22 or 006P 5 Rejoin the case bottom and battery compartment and reinstall the screw D Replacing the Fuses see figure 4 Warning To avoid electrical shock or arc blast or personal injury or damage to the Meter use specified fuses ONLY in ...

Page 31: ... the fuse by gently prying one end loose then take out the fuse from its bracket 5 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 Ceramic fuse 0 5A 600V fast type φ5x20mm Fuse 2 Ceramic fuse 20A 600V fast type φ6x25 mm 6 Rejoin the battery compartment and the case top and reinstall the screw 7 Rejoin ...

Page 32: ...VC820 VC840 OPERATING MANUAL 32 A Connect with computer Connect the Meter with a computer using RS232C serial port as shown in figure5 ...

Page 33: ...25 Pin Female Pin Name 2 2 3 RX 3 3 2 TX 4 4 20 DTR 5 5 7 GND 6 6 6 DSR 7 7 4 RTS 8 8 5 CTS C Setting of RS232C Serial Ports Default of RS232C serial port for communication is set as Baud Rate 2400 Start bit 1 always 0 Stop bit 1 always 1 Data bits 7 Parity Odd D System Requirements for Computer Interface Software ...

Page 34: ...ive z Can access to a local or a network CD ROM z A free serial port z A mouse or other pointing device supported by Windows Please refer to VC820 VC840Computer Interface Software for installation and operation instructions of the Interface Software END This operating manual is subject to change without notice Manufacturer Uni Trend International Limited Rm901 9 F Nanyang Plaza 57 Hung To Road Kwu...

Page 35: ...ease follow below procedure Before install the interface program make sure that the computer is running the Window 95 or above operating system 1 Insert the provided CD ROM into CD ROM drive Double click the My Computer icon from the Windows desktop Locate the CD ROM drive from the window double click the drive letter to display the folder of vc820_840 Double click vc820_840 to display the content...

Page 36: ...select corresponding COM 1 2 3 4 4 Press Connect from menu bar to start the connection the icon will be displayed D Graphical Operations see figure 1 During the connection you can select the following functions by clicking the corresponding icon Fill Click the box to select fill up graph or unclick to select line graph Record Setting the number of record to show on graph Clear To clear all the gra...

Page 37: ... 2 During the connection you can select the following functions by clicking the corresponding icon Repeat Click the box to keep the repeat record or unclick the box to ignore the repeat record Graphic Selection No of records setting Clear Save First Previous Next Last Zoom In Fill Up Graph ...

Page 38: ...click to disable the function Enter the sampling interval time the unit is second Clear To clear all the records permanently Save To save all the record figure 2 F Max Min Operations see figure 3 MIN Recorded maximum value Keep or ignore the repeat record Sampling interval selecting Enter the time Clear Save ...

Page 39: ...Enter the lower limit value in full digit it does not identify range or function The Meter is connected properly to the computer and data is recording OL Overload the recorded value exceeds the SetMax and SetMin value It will be flashing and the computer will sound if loudspeaker is installed figure 3 Enable SetMax function Recorded maximum value Recorded minimum value Upper limit setting Lower li...

Page 40: ...ove font UNIT A2 and then install new font set from FONT directory on the provided CD ROM 3 No special notice or free replacement will be provided when update version is issued END This operating manual is subject to change without notice Manufacturer Uni Trend International 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 u...

Page 41: ...VC820 VC840 Computer Interface Software 7 ...