# Accuracy Component Tester.

Discussion in 'General Electronics Discussion' started by caps, Oct 13, 2018.

1. ### caps

155
8
Jul 29, 2018
Hi all
Who was interested in what the measurement accuracy in the transistor tester?

2. ### caps

155
8
Jul 29, 2018
Resistor 1 Ohm 1%.

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155
8
Jul 29, 2018
0,1 Ohm 1%.

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4. ### ratstar

54
0
Aug 20, 2018
1% error sounds really great until your talking about pico amps, then its 0.00001% accuracy required i think.

5. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,363
2,758
Jan 21, 2010
Why? My picoammeter is around a couple of percent accurate. It works fine.

I think you misunderstand what accuracy means.

6. ### BobK

7,680
1,685
Jan 5, 2010
Um... A 0.1Ω resistor read as 0.11Ω is off by 10%. To be 1% it would have to be between 0.099 and 0.101.

The error has to be calculated as a percentage of the correct value.

Bob

7. ### caps

155
8
Jul 29, 2018
In order to measure 0,101Ohm, it lacks resolution.

8. ### caps

155
8
Jul 29, 2018
Precision resistor 0,01 Ohm 1%.

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9. ### BobK

7,680
1,685
Jan 5, 2010
You cannot have more accuracy than you have resolution. But the reverse is not true.

In your 0.01 example, if it can only display the 1/100 digit, the true measurement might be anywhere from 0.0005 to 0.015 and it would display 0.01. So the precision is about 50%

Bob

10. ### Ratch

1,073
327
Mar 10, 2013
What parameter of the transistor is the transistor tester measuring?

Ratch

11. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,363
2,758
Jan 21, 2010
Resistance :-?

12. ### Ratch

1,073
327
Mar 10, 2013
Don't think so. The resistance of a semiconductor varies with the voltage of the ohmmeter. It does not follow Ohm's law.

Ratch

13. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,363
2,758
Jan 21, 2010
Exactly.

We haven't seen any measurements you'd typically associate with a transistor.

But I know these devices do them.

Of what they test, I'm not sure you need any particular level of accuracy. Even if you want to find closely matched devices, all you need is something which produces repeatable (and possibly reasonably precise) results, not necessarily highly accurate ones.

14. ### kellys_eye

4,276
1,146
Jun 25, 2010
Personally I'd use a resistance meter to test a resistor and leave 'that' particular test device for what it was originally intended - semiconductors.

15. ### Ratch

1,073
327
Mar 10, 2013
The OP wrote "transistor tester". Perhaps he meant transistorized tester (ohmmeter).

Ratch

16. ### Ratch

1,073
327
Mar 10, 2013
Too bad this testor is not manufactured anymore. It did a quick check on a transistor by determining if it could invert a pulse. http://www.cbtricks.com/miscellaneo...ore_tf26_cricket_full_sm_with_corrections.pdf

Ratch

17. ### kellys_eye

4,276
1,146
Jun 25, 2010
Nope, the screen (LCD) display is that of one of those cheapo Chinese 'multi-tester' devices.

18. ### Hopup

253
35
Jul 5, 2015
I myself have one of these cheap meters and it is pretty useful, have not used it for transistors other than initial testing of the device. They should be able to detect Hfe, Ube and other parameters, but if I remember right, the results were not very good.

155
8
Jul 29, 2018
Resistance.

20. ### caps

155
8
Jul 29, 2018
Precision resistance.
1,8к 1%.
3,16к 0,1%.

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