PUBLIC Forums => Public Forums => Call For Assistance Feedback => Topic started by: kgarrison on January 09, 2020, 07:26:02 PM

Title: Caliper calibration vendor
Post by: kgarrison on January 09, 2020, 07:26:02 PM
My lab is starting to determine uncertainty for our various measurement equipment.


Does anyone have good recommendations for vendors to use (or stay away from) in the southwest part of the U.S.?


I have specifically been tasked with finding a vendor who calibrates calipers, but I know these vendors usually are certified to perform calibrations on several different pieces of equipment.


They would need to be up to ISO accreditation standards and be able to provide documentation of traceability to SI units.


Feel free to reply here or email me at kgarrison@sbcsd.org


Thanks in advance!
Title: Re: Caliper calibration vendor
Post by: Julie Knapp on January 10, 2020, 10:21:51 AM
Are you going to use a measurement standard like a gauge block?
Title: Re: Caliper calibration vendor
Post by: Julie Knapp on January 10, 2020, 10:28:39 AM
We just got our gage blocks recertified for Colorado Bureau of Investigation and used Applied Technical Services out of GA.  No issues and they had them back to us very quickly.
If you have not purchased gage blocks yet and want to,  you can purchase them already certified.  Then, depending on your specified recert. schedule, you would just need to send those out.  You can then use your gage blocks to do your calipers and micrometers; although I prefer a glass slide micrometer to test my digital micrometer...here is a website you can check out:
https://www.pcsllctn.com/services/dimensional-calibration/gage-block-calibration-service/ (https://www.pcsllctn.com/services/dimensional-calibration/gage-block-calibration-service/)

there are other sites, this is just one. 

:)
Title: Re: Caliper calibration vendor
Post by: Alan Zheng on January 13, 2020, 10:12:19 AM

You can use this to search for certified calibration of just about anything.

https://cabportal.touchstone.a2la.org/index.cfm?event=directory.index (https://cabportal.touchstone.a2la.org/index.cfm?event=directory.index)
Title: Re: Caliper calibration vendor
Post by: kgarrison on January 14, 2020, 01:59:42 PM
Are you going to use a measurement standard like a gauge block?


We have our certified gauge blocks we use on a quarterly schedule to do checks on the calipers.


The problem we discovered was that the calipers themselves need to be sent out to be calibrated and certified as well.
Title: Re: Caliper calibration vendor
Post by: Nat Pearlson on January 16, 2020, 09:22:17 AM
If your lab requires you to have the caliper as well as the gauge blocks certified, then you have to do it.  I don't think accreditation requirements mandate that.  If you are checking your calipers against a traceable reference standard (appropriately certified gauge blocks), I believe you are meeting accreditation requirements, at least for ANAB.

Nat
Title: Re: Caliper calibration vendor
Post by: Jennifer Floyd on January 17, 2020, 01:32:46 PM
Nat - it would be because they are calculating uncertainty.  The device you use to make the measurement has to be calibrated prior to service and you include the measurement uncertainty found by the calibrating service when you calculate the uncertainty for a certain measurement type.
Title: Re: Caliper calibration vendor
Post by: Nat Pearlson on January 17, 2020, 03:19:22 PM
Good point Jennifer.  I was thinking of the calipers we use for measuring bullets, tools, etc. for which we don't calculate an uncertainty for (yet!).  For our large calipers that we are implementing for firearm length measurement, as Jennifer says, we included the uncertainty on the calibration certificate of for the calipers in the budget for the uncertainty of the measuring process.

Nat
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