Accuracy of test instrument

[lofty84]

state three methods for checking the accuracy of test equiptment.

calibration
check box
check against someone elses meter

can you think of anymore ?

If an instrument is found to be inacurate after tests have been completed list three ations which should be taken

what would be your standard procedure for this ?

 

[tony mc]

I would re check the meter and make sure the batterys are in good order. (Could be that simple especially if its a1552) as per manufacturers instructions.

Check the meter against another meter to see if the readings differ or check box / both.

Have the meter re calibrated repaired if still not accurate.

You would need to re test the previous things to make sure everything is in order.

You would normally have a rough idea of what the test results are giong to be so alarm bells should be ringing quickly.

 

[Martin Bradley]

known resistor values. like my little box, home made lol
make your own check box

 

[lofty84]

nice gadget Bradzz

what about send it of for calibration and re do tests, let people know about suspect results, let client know also

 

[Knobhead]

The last time I sent a Fluke to Dowding & Mills the company I worked for complained it would have been cheaper to buy a new one. D&M is where the company all sent all the instruments off the plant. Can’t do right for doing

 

[Martin Bradley]

its accuracy was checked against calibrated equipment, its a just incase you drop your tester box, then you can check it against a bench mark, and previous tests, do you realy know how often your tester should be checked?
look it up and you might be suprised.
and yes i do have all my equipment calibrated, onsite calibration, are a good company.
but you was asking about diff methods and mine is one.
and dont forget a resistance value of 1 ohm will still be 1 ohm the next day ?
Lofty,check out IQ post, sounds good to me.
just because i made my own little resistance check box dont mean it aint any good, or would you rather pay someone to make you one. the NICEIC like that i had one even though it was a home made one, as not many sparks have a check box.

 

[IQ Electrical]

Guys, this whole calibration thing is so misunderstood, not just by electricians but assessors too!

The problem is that a calibration company will calibrate your thermos flask if you ask them to, no mention will be made of any requirements to calibrate or not!

Have a read of this : http://www.esc.org.uk/fileadmin/user_upload/documents/industry/best_practice/BPG7_10.pdf

 

[Golden_Boy]

nice gadget Bradzz

what about send it of for calibration and re do tests, let people know about suspect results, let client know also

When test equipment is "tested for accuracy" its not "Calibrated" at all ? So why call it "calibration". Does anyone know exactly how modern testers are calibrated? I would assume a firmware tweek would be involved as there would appear to be nothing to physically adjust ( at least not in the stuff i've seen inside of?? Its one of these areas that makes me go MMMMMMM....

 

[IQ Electrical]

When test equipment is "tested for accuracy" its not "Calibrated" at all ? So why call it "calibration". Does anyone know exactly how modern testers are calibrated? I would assume a firmware tweek would be involved as there would appear to be nothing to physically adjust ( at least not in the stuff i've seen inside of?? Its one of these areas that makes me go MMMMMMM....

Exactly my point.

 

[Golden_Boy]

Exactly my point.

I have asked this question several times and have yet to receive a satisfactory answer.
It wouls appear that " we will check your kit against ours and tell you how good/bad it is" sounds a lot less technical than "Calibration"

 

[IQ Electrical]

Snake oil.

 

[Golden_Boy]

Snake oil.

And LOTS of it......... ( unless someone knows diffrent )

 

[Martin Bradley]

No it works for me stops my boots squeaking. lol

 

[Golden_Boy]

When test equipment is "tested for accuracy" its not "Calibrated" at all ? So why call it "calibration". Does anyone know exactly how modern testers are calibrated? I would assume a firmware tweek would be involved as there would appear to be nothing to physically adjust ( at least not in the stuff i've seen inside of?? Its one of these areas that makes me go MMMMMMM....

No takers then????????????
Come on all you "calibration" folk ... defend yourselves..............
Dont worry about being technical.. we can take it...

 

[UNG]

and dont forget a resistance value of 1 ohm will still be 1 ohm the next day ?

Depends on the ambient temperature on both days as resistance varies with temperature. That is why you may get inconsistent readings when taking your meter from a cold van into a warm building as the meter acclimatises to the ambient temperature the test results will vary until the meter reaches ambient temperature

just because i made my own little resistance check box dont mean it aint any good, or would you rather pay someone to make you one. the NICEIC like that i had one even though it was a home made one, as not many sparks have a check box.

I just use a collection of resistors why pay £'s for a fancy box when pennies will buy you a handful of resistors that will do the same job