Fluke 375 clamp meter with large DC current offset

[radioFlash]

I have a Fluke 375 which is showing a large offset in the DC current mode without any wire or current (see image). The photo was taken while the meter was on a metal chair, but the negative reading doesn't change much if I move it around. I just received this meter so I'm not familiar with how it should normally operate.

Turning it off and on has no effect. The batteries in the meter measure fine. The zero button does nothing when I press it except chirp. The DC V and Ohms mode seem to work correctly. If I do put a DC current (say 1 A), the reading does change to reflect the current, so the meter is detecting a change (the reading changes by 1A). Is this a case of user error and there's a simple way to zero it out, or does it need to be re-calibrated, or is it broken and needs to be fixed?


Thanks for any suggestions.

[MarkL]

It looks broken to me.

I have the 376 and it starts up with DC offset of 0.4A to 0.5A but goes to 0.0A once the Zero button is pressed.  Yours should do the same.

[retiredcaps]

This recall notice shouldn't be the cause of your readings (26A offset), but you should check anyway.

http://www.fluke.com/fluke/caen/about/press/digital-clamp-meter-recall

[radioFlash]

It looks broken to me.

I have the 376 and it starts up with DC offset of 0.4A to 0.5A but goes to 0.0A once the Zero button is pressed.  Yours should do the same.

Thanks for the confirmation, that's what I expected.

[radioFlash]

This recall notice shouldn't be the cause of your readings (26A offset), but you should check anyway.

http://www.fluke.com/fluke/caen/about/press/digital-clamp-meter-recall

Thanks for the info, interesting to know. And thanks for all the other answers you've given to others when they asked for help too!

[walter.aranda]

Hello, I have a Fluke 376 FC with the same problem of a 1.3A DC offset in its default setting. Since I don't have a Fluke warranty because I live in a third-world country, I decided to fix it on my own. Maybe this will help you solve your problem as I did:

1. Turn off the multimeter.
2. Open the battery cover; it's not necessary to remove the batteries.
3. Remove the two Phillips-type screws.
4. The circuit has a single surface-mounted metallic potentiometer. You should carefully adjust it clockwise or counterclockwise in very small increments (take a photo beforehand to remember its original position).
5. With each slight adjustment, cover the clamp and check the new offset. Repeat these steps until the offset is zeroed out.
NOTE: It's recommended to use Loctite 243 after finishing, as it seems the manufacturer overlooked protecting this single potentiometer from mechanical movement due to use.
In my case, it worked with a very slight movement.
I am not responsible for improper procedures.
Good luck!