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How much accuracy do YOU really need?
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TomKatt:
I know that there are many folks here with technical skills WAY above mine, so just curious about how accurate you need your test gear to be...

It struck me that 99% of the time I just need 'ballpark' readings to confirm if something is operating within a known set of parameters.  My projects vary from small ucontroller (AVR/PI) digital circuits to audio / amp repair and finally computers, household appliances and automotive work.  Few instances require great accuracy.

It seems that repeatability is more important to many things I measure - is the bias on the left channel the same as the right (no matter the actual voltage measurement)?  Or adjust something for minimum or maximum deflection.  It's amazing how tolerant so many circuits appear to be - audio tube amps run on double digit tolerance parts and it never ceases to amaze me when Shango066 gets an old tube tv running that's been sitting in dried mud for 20 years simply by replacing a few caps and a burned resistor.

I am cognizant of the spec'd accuracy when I buy gear, but most of the time it's not in my top 5 criteria...  Most modern 'decent' gear seems "good enough".  There are obviously times when a few millivolts or ma will make or break something operating correctly, but I'm not sure how many times I based that on my readings rather than tweaking things and observing the results.

SO - How do YOU folks rate gear accuracy in your work?

edit -autocorrect corrections ;-)
BradC:
I'm often looking at repeatable discrepancies, so it's not accuracy so much as precision I need.
tom66:
For day-to-day usage of a multimeter?  0.1-0.2% accuracy is probably OK.  That eliminates the multimeter as a likely source of error in most systems I work on.  However as mentioned, I would agree that repeatability is far more important, so if that 0.2% error is consistent across all ranges (for e.g. voltage, it is a 'reference' error rather than a 'gain' error) is better than one where the individual ranges are scattered in accuracy.  It's also important it doesn't vary with battery state of charge (looking at you, "bottom of toolbox emergency multimeter") or too much over time and temperature.
TomKatt:

--- Quote from: tom66 on February 09, 2023, 11:34:14 am ---For day-to-day usage of a multimeter?
--- End quote ---
I'm curious about all equipment.  I agree with your sentiments about the DMM's.  But even when I pull out the scope, I'm not sure how many times I relied on it's accuracy either...  Certainly I got by for many years using my ancient HP180A cro.

While I don't do much with RF, that's one field where I suspect true accuracy might be an important spec (then again - the Shango066 tv example.  Love the way he tests caps by playing phone audio through them and listening for the filtering)
Bud:
You picked a poor example, the guy even never bothers to blow the 50 year dust off of the poor TVs before poking his crude tools in them.
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