Analog voltmeter does not go back to zero

crutschow

Well-Known Member

Most Helpful Member

• Today at 8:15 AM

• #2

Does the meter not go back to zero when the DAC signal is physically removed?

 

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R

remzo

New Member

• Today at 8:17 AM

• #3

Yes. (I just found out a video is not allowed... )

Click to expand...

 

Last edited: Today at 8:23 AM

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L

Les Jones

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• Today at 9:35 AM

• #4

As crutschow's question is "Does the meter NOT go back to zero" when the meter is disconnected from the DAC do you mean that it does NOT go back to zero ?

Les.

 

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R

remzo

New Member

• Today at 10:41 AM

• #5

It does not go back to zero indeed. In the photo the volt meter is disconnected.

If I switch + and - the DAC signal makes the meter go to zero (and it tries to go even lower).

 

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JimB

Super Moderator

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• Today at 10:52 AM

• #6

The mechanical "zero adjustment" mechanism has been disturbed, I guess by your fingers when you picked up the meter.




Try moving the the part indicated by the red arrow.
When that part is vertical, the meter pointer should be at zero.

JimB

 

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Solution

Nigel Goodwin

Super Moderator

Most Helpful Member

• Today at 10:52 AM

• #7

remzo said:

It does not go back to zero indeed. In the photo the volt meter is disconnected.

If I switch + and - the DAC signal makes the meter go to zero (and it tries to go even lower).

Click to expand...

The mechanical zero adjustment on the meter needs setting properly, as JimB has just posted as I was typing

 

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Nigel Goodwin

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• Today at 10:54 AM

• #8

A further point, why has the meter been removed from it's casing?, there will be an adjusting screw on the casing.

 

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D

Diver300

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• Today at 10:55 AM

• #9

I was just about to say what JimB said, and Nigel was about to say.

I think some engineers of a certain age have experience of analogue meters.

 

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R

remzo

New Member

• Today at 11:30 AM

• #10

Thanks JimB, Nigel and Diver300, it was exactly that unnamed thingy. The adjusting screw corrects a little bit but not so much.

I've another voltmeter with the same problem and will take a look at that one too.

 

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L

Les Jones

Well-Known Member

Most Helpful Member

• Today at 11:53 AM

• #11

I think that some dirt has got in between the coil and the magnet. Just moving the zero adjustment by accedent should give readings that were consistently out by the zero offset error.

Les.

 

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