×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

standard calibration tolerance

standard calibration tolerance

standard calibration tolerance

(OP)
Dear Gents

I need to know if there is any standard for accepted calibration tolerance for PT, Thermocouples,RTD,....

Best Regards

RE: standard calibration tolerance

Not really...
There are tolerances for devices like a 1% TC or 3% extension wire, but each user needs to define the accuracy and tolerance their particular case warrants.  More accuracy = more money.  You should figure out your requirements and go from there.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: standard calibration tolerance

Your question does not quite compute.  Which calibration accuracy are you refering to?  The actual sensor uncertainty? or the calibrator uncertainty?

Your sensor uncertainty should be whatever is the specification for it.

Your calibrator uncertainty, traditionally, per MIL-HBK-52 is 1/10th the sensor uncertainty.  However, it is generally accepted that a 4:1 test accuracy ratio is adequate.

TTFN

FAQ731-376: Eng-Tips.com Forum Policies

RE: standard calibration tolerance

(OP)
I mean if i am calibrating a transmitter by  a certified calibrator, when i can accept this transmitter and when it is not accepted and i will need to replace the transmitter sensor module

RE: standard calibration tolerance

Sorry, still not making sense.  Is this "certified calibrator" a person or an instrument?  If the former, then they should know what to do with your transmitter.  

If the latter, what is your specification?  Is it in spec or not?  If not, is there a means of correcting the readings to be more correct?  If not, then, yes, you have to deal with an instrument that doesn't meet specification?

If you don't know what the specification is, then ASK the manufacturer.

TTFN

FAQ731-376: Eng-Tips.com Forum Policies

RE: standard calibration tolerance

What context?

Consider accuracy and precision to be commercial or contractual requirements.  Does the contract include an accuracy requirement?  Does the manufacturer make an accuracy claim?  Assure that the latter is better than the former.  Test to comply with the contractual requirements.  Verify that the test instruments have a current calibration traceable to the NIS or such organization.  Again the contract may define "current".

Six months test instrument calibration and about 0.5% accuracy may be about a good as you could expect for construction checkout of field instruments.  Expect less for very low dp and for thermocouple temperature.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources