Voltmeter digital

[Alan194616]

CE05109. And CE05133

What is the overall accuracy before displaying of Dc v readout. ??

I understand at between 11-14v. It only shows to 0.1 v on display

And in picture is that a pot on rear of unit which will allow us to fine tune the voltage output reading ??

We have some test equipment that can measure voltage down to 0.02v DC at our 11-14v , so can adjust the readout if necessary for more accurate display if pot adjusts this

[Robert93820]

Hi Alan
The “accuracy” is published on Core web site
CE05133 = * Error: 1%
CE05109 = * Accuracy: 0.01V < 10V, 0.1V > 10V
I personally would not touch any pots. You will not improve the overall accuracy.
If the quoted figures do not suit you should purchase a unit that will do the job. I don’t think these units are really meant to carry out precise measurements, just a comparative indication. Unless your comparison meter is a pretty up market unit with a current calibration certificate I would treat this absolute measurement with some reservation. For instance I have 3 DMMs, all of different age and “quality” and the variation can be up to 100mV or more. This does not bother me as I know about it and interpret any measurements accordingly.

I guess what I am getting at here in all my years at this business I have not found too many circumstances where 1 decimal place is not adequate. Particularly when you get up a bit in volts. You really need to get down to 1 or 2 volts where the second decimal place becomes significant and in some circumstances critical.
Cheers Bob

[Robert93820]

Hi Alan
Add on to above post
For your information.
This is the DC spec for my newest (and most expensive) DMM. It is nearly 10 yrs old now and I have never had the calibration checked so I would not be able to guarantee the accuracy. One of the important figures is the + number for the least significant digit correction. When you get to AC voltage this number increases to 40 you could pretty well ignore the last 2 digits. And this is for a fairly good quality meter. These figures should be published for all meters but unfortunately rarely are to this level of completeness.

Uni-T publish for all measuring functions in the handbook.
I also have a uni-T clamp meter which gets down to milliamps and is surprisingly accurate when the wire is in the centre and current the right direction.
Cheers Bob