So the question stays: can the mechanism be calibrated/adjusted?
Peter
Yes, it can be done. It will be time consuming and not necessarily cost effective.
The refurbished unit you have received is probably performing on par with the manufacturer expectations. Pawel brought up 2 very important points here;
1. part of the standard measurement error is the error you make while reading the scale.
2. Then comes the error related to the precision of the instruments.
I would like to touch on the second point. General use electronic components will hover in 5 to 10% tolerance. To dip down to 1% it will easily double your cost. Than we can also find extreme application components still cut those tolerances in half. They are not cheap and from the business point of view almost impossible to justify. Since we are referencing our analog reading against the partial scale the final outcome is the personal interpretation of the person reading it.
Next comes the tolerance of the testing equipment used. Personally I own 4 temp tester and they all perform well in their respective tasks. Now if I was to take them out of their preferred range the reading results would become less accurate. What I’m getting at here is the application limitations. As you already noticed your “error” is much lower in the centre of the scale and that is directly related to the device range. Your mid scale will produce more linear and accurate results while extremes will lack that quality.
Testing equipment in that situation must be reference quality. We are trying to calibrate after all. Adjustments can be carried out with parallel resistance to move the flatter response up the scale.
If you want to do it just to see if you can do it. Sure knock yourself out.
If the claim of the most accurate gauge is your aim than forget it. You may have a fit after your best body tells you that it looks like your gauge is reading low.
