Perth - who does DMM calibrations?

"Dennis"

** You need to be able to check the DMM for basic accuracy any time you like.

For that you need a precision voltage reference and a few precision resistors.

This is a 10 volt, 0.0025% reference for under $9 inc. gst.

Resistors of 0.1% accuracy are available from 10 ohms to 1Mohm for $1.31.each.

Buy a few, so each ohms range is covered.

20 bucks or so and you have it.

.... Phil

Thanks Phil - I need it calibrated by a third party as I use it in work for others who want it calibrated. Your idea of having a means of testing it periodically is good. Thats a bloody good reference for

"Dennis"

** You stated that no certificate was required and only a " basic calibration " is needed.

I think you and your colleagues are misguided about the supposed benefits of external calibration services - cos that only ever prove the point on *one day* in the past.

If you add a series string of 0.1% resistors ( or 0.01 % types of you can afford them ) to that 10 volt reference that divided the voltage by 10 and

100 etc - you have a reference you can use to check most of the DC voltage ranges on a daily basis or whenever a critical measurement is made.

.... Phil

I only meant that a "NATA" style cert wasn't needed. As you can no doubt tell I'm not up to date on what the options are. 20 odd years ago I remember there were a couple of grades of calibration - with the price going up depending on what level of cal was done. IIRC RS & Farnell used to offer different cals on the TEQ they were selling.

I tend agree that the cal is only good for the "day" it was done, but the company that wants it done it the one that pays the bills....

I'll grab that ref you suggested and a few of resistors.

"Dennis"

** Think they sent the items back to the UK.

I once purchased a TTI bench meter from them ( Farnell) and returned it cos it has so many bugs.

A second example had the exact same bugs and was covered in finger prints and strawberry jam.

It was a TTI 1604 - I see the god awful POS is still on sale.

** Bureaucratic thinking.

Always more impressed by scraps of paper in preference to anything real.

** Something tangible, you can trust.

.... Phil