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Multimeter (Vc88c) Reading Temperature Wrong

dark phobia

Dec 22, 2014
6
Joined
Dec 22, 2014
Messages
6
I broke my multimeter(Vİctor Vc88c). Everything is working charm except temperature. Multimeter display wrong temp. Like -250℃. I am not measure temp often but i want to repair if its possible.
So I didn't find my multimeter scheme on the internet. I found two multimeter that has similar technical properties. I think vc9805a and ut70a are look like my multimeter. And ut70a inside looked very similar to me. What might be the problem? I want to know which part of the schemes are related with temperature measurement. Need help. Thankyou...

Victor VC88C 3 1/2 Digital Multimeter


FEATURES
·New type holster, stream
line design
·Large LCD makes the reading clearly.
·Metallic screen board with stronger antimagnetic and anti-interferential function.
·No power off under natural operation.
·Full function protection, anti-high voltage circuit design.

Basic Function Range Basic accuracy
DC Voltage 200mV/2V/20V/200V/1000V ±(0.5%+3)
AC Voltage 2V/20V/200V/750V  
200mV/2V/20V/200V/750V ±(0.8%+5)
DC Current 20uA/200uA/20mA/200mA/2A/20A  
20mA/200mA/20A  
2mA/20mA/200mA/20A ±(0.8%+3)
AC Current 200mA/2A/20A  
20mA/200mA/20A  
2mA/20mA/200mA/20A ±(1.0%+5)
Resistance 200Ω/2kΩ/20kΩ/200kΩ/2MΩ/200MΩ  
200Ω/2kΩ/20kΩ/200kΩ/2MΩ/20MΩ/2000MΩ ±(0.8%+3)
Capacitance 20nF/2uF/200uF  
20nF/200nF/2uF/20uF/200uF ±(2.5%+20)
Frequency 2kHz/200kHz  
2kHz/20kHz/200kHz/2000kHz/10MHz ±(0.5%+4)
Inductance 2mH/20mH/200mH/2H/20H ±(2.5%+20)
Celsius (-40~1000)℃ ±(1.0%+4)

Special Function
Diode test √
Continuity buzzer √
Low battery indication √
Data Hold √
Auto power off √
Backlight √
Function protection √
Restorable Fuse protection √
Shock proof protection √
Input impedance 10МΩ
Sampling rate 3 times/s
AC Frequency response 40~400Hz
Operation way Manual range
Max. Display 1999
LCD size 65×45mm
Battery 9V(6F22)

VC9805A+ 3-1/2 Digital Multimeter


Detail:
·New type hols
ter, streamline design.
·Large LCD makes the reading clearly.
·Metallic screen board with stronger antimagnetic and anti-interferential function.
·No power off under natural operation.
·Full function protection, anti-high voltage circuit design.
·New type battery case design, it’s easy to change battery.
Basic Function
Range
Accuracy

DC Voltage
200mV/2V/20V/200V/1000V±(0.5%+3)
AC Voltage200mV/2V/20V/200V/750V±(0.8%+5)
DC Current2mA/20mA/200mA/20A±(0.8%+10)
AC Current2mA/20mA/200mA/20A±(1.0%+15)
Resistance200Ω/2kΩ/20kΩ/200kΩ/2MΩ/20MΩ±(0.8%+3)
Inductance2mH/20mH/200mH/2H/20H±(2.5%+30)
Capacitance20nF/200nF/2uF/20uF/200uF±(2.5%+20)
Frequency2kHz/20kHz/200kHz/2000kHz/10MHz±(3.0%+18)
Celsius(-40~1000)ºC±(1.0%+5)
Fahrenheit(0~1832)ºF±(0.75%+5)


Special Function

Diode√
Transistor test√
Continuity buzzer√
Low battery indication√
Hold
Data hold
Auto power off√
Backlight√
Function protection√
Shockproof protection√
Input impedance10MΩ
Sampling rate3 times/s
AC Frequency response40~400Hz
Operation way Manual range
Max. Display1999
LCD size70×50mm
Battery9V (6F22)
Product color
Case: dark gray; Holster color: yellow
Product Net Weight
Approx:320g
Product Dimension
190×88.5×27.5mm
Standard Accessories
Test leads, battery, instruction manual, TP01
temperature probe (with temperature function)
Standard inner packing
Color box


UNI-T UT70A

SPECIFICATIONS
Basic Functions
Range Best Accuracy
DC Voltage
200mV/2V/20V/200V/1000V
PLUSMN.GIF
(0.5%+1)
AC Voltage 200mV/2V/20V/200V/750V
PLUSMN.GIF
(0.8%+3)
DC Current 20mA/2mA/200mA/10A
PLUSMN.GIF
(0.8%+1)
AC Current 20mA/2mA/200mA/10A
PLUSMN.GIF
(1%+3)
Resistance 200W/2kW/20kW/200kW/2MW/20MW/2000MW
PLUSMN.GIF
(0.8%+1)
Capacitance 20nF/200nF/ 2mF/100mF
PLUSMN.GIF
(2.5%+5)
Temperture(°C) -40°C~1000°C
PLUSMN.GIF
(1%+3)
Temperture(°F) -40°F~1832°F
PLUSMN.GIF
(1%+4)
Frequency 2kHz -10MHz(Auto Ranging)
PLUSMN.GIF
(0.1%+3)
Inductance 2mH/20mH/200mH/20H
PLUSMN.GIF
(2%+10)
Logic TTL (High > 2.0V, Low < 0.8)
TICK.GIF

Special Functions
Fused 10A Range
TICK.GIF

Diode
TICK.GIF

Continuity Buzzer
TICK.GIF

Transistor
TICK.GIF

Peak Hold
TICK.GIF

Data Hold
TICK.GIF

Display Backlight
TICK.GIF

Full Icon Display
TICK.GIF

Sleep Mode
TICK.GIF

Low Battery Display
TICK.GIF

Max. Display 1999
TICK.GIF

GENERAL CHARACTERISTICS
Power
9V Battery (6F22)
LCD Size 62 x 53mm
Product Colour UT70A - Grey, Holster - Red
Product Net Weight 620g (including holster)
Product Size 195 x 90 x 40mm
Standard Accessories Test Lead, Battery, English Manual, Point Contact Temperature Probe, Test Clip, Multi-Purpose Socket, Holster
Optional Accessories* Clip-On Test Lead Light (UT-TL), Built-In Test Lead Light (UT-L1), Built-In Test Lead Light Plus (UT-L2), Carrying Bag
Standard Packing Gift Box
Standard Quantity Per Carton 20 pcs
Standard Carton Measurement 535 x 365 x 380mm (Around 0.074 CBM Per Standard Carton)
Standard Carton Gross Weight 22.7kg
 

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KrisBlueNZ

Sadly passed away in 2015
Nov 28, 2011
8,393
Joined
Nov 28, 2011
Messages
8,393
It looks like the temperature probe connects through the µA/mA connector. Check that the fuse on that connector is not blown. I have no other suggestions.
 

dark phobia

Dec 22, 2014
6
Joined
Dec 22, 2014
Messages
6
I have only this multimeter so i can't measure. I calibrated the temperature vr5 and vr6 -320℃ at room. I measured hot water as 397℃. Multimeter working reverse but i think it is enough.

When i connect to 1k ohm resistor to R17 reading temperature is get better and display +30℃. I have no smd resistor now i will try to change after i got.
 

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KrisBlueNZ

Sadly passed away in 2015
Nov 28, 2011
8,393
Joined
Nov 28, 2011
Messages
8,393
I have only this multimeter so i can't measure.
There are lots of ways to check a fuse without using a multimeter. In this case you can check it by (a) connecting your temperature probe, selecting the temperature range, and bridging the fuse with a pair of pliers - if the temperature indication comes right, you know the fuse is open, or (b) checking that the multimeter can measure current on the µA/mA range.
 
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