Maker Pro
Maker Pro

Multimeter issue

Jujigatame

Sep 5, 2021
5
Joined
Sep 5, 2021
Messages
5
Hello everyone.
I am trying to measure the current from electirc circuit. There is a arduino power supply which I measured on resistor and value is 3.8V. Resistor is 180 ohms which means that I need to get current value of 0.021A but when I measured it with multimeter with range in miliAmps it displays 0.4mA and in micro 4.0 microAmps and with regular Amps it is 0.02 . I don't know what is the problem.

I have two inputs for my positive lead. One is for V, mA, microA and ohms, other is for 10A MAX. Options for measuring Amps are 200microA , 200miliA, 10A. When I plug the lead to 10A and i choose measurement 10A it gives good calculation, but when I plug the lead for mA,microA and choose the option to measure in mA and microA it proveds different results. For example lead in 10A and 10A measurement gives 0.02 which is correct but lead in mA with mA measurement gives 0.4
 
Last edited:

bertus

Moderator
Nov 8, 2019
2,641
Joined
Nov 8, 2019
Messages
2,641
Hello,

I see the meter has only three ampere settings:
UNI-T-UT131B.jpg
In the 200 μA range, it will be out of range.
In the 200 mA range, it should show 21.1 mA.
In the 10 Amp range, it will show 0.

Bertus
 

Jujigatame

Sep 5, 2021
5
Joined
Sep 5, 2021
Messages
5
Hello,

I see the meter has only three ampere settings:
View attachment 52837
In the 200 μA range, it will be out of range.
In the 200 mA range, it should show 21.1 mA.
In the 10 Amp range, it will show 0.

Bertus
Okay, so when I use 15V and 180 ohm resistor that is 0.083A that I need to measure. 10Amp range shows 0.08 which is correct, but at 200mA range it is 3.3mA and how could that be?
 

bertus

Moderator
Nov 8, 2019
2,641
Joined
Nov 8, 2019
Messages
2,641
Hello,

You are measuring in series with the load.
In the 10 Amp range the resistance of the current sensing resistor is much lower as the 200 mA range.
It sounds there is something wrong in the 200 mA range.
It could be the sensing resistor or a switch issue.

Bertus
 

Jujigatame

Sep 5, 2021
5
Joined
Sep 5, 2021
Messages
5
Hello,

You are measuring in series with the load.
In the 10 Amp range the resistance of the current sensing resistor is much lower as the 200 mA range.
It sounds there is something wrong in the 200 mA range.
It could be the sensing resistor or a switch issue.

Bertus
It is probably broken. I borrowed another multimeter and it's fine now.
Thank you for helping.
 
Top