Reference thermometer calibration frequency
Hi everyone, I have a question about my reference thermometer calibration frequency. last year I purchased a certified NIST thermometer to be used as a reference to verify the thermometers used in the production floor. The certificate of calibration has an issue date but not an expiration date. How often should I send it out for recalibration or get a new one? I called Thermoworks and they told me they don't give an expiration date, just issue date
We send our Mercury in Glass Thermometer out every year to be calibrated. I don't know what you have. but you have to write it in your program how you are verifying that piece of equipment is accurate.
We send our Mercury in Glass Thermometer out every year to be calibrated. I don't know what you have. but you have to write it in your program how you are verifying that piece of equipment is accurate.
This is the kind that I have.
https://www.thermowo...kBoCoLUQAvD_BwE
The one I used before this one had an expiration date after 2 years so I just went with that but I'm guessing I will have to update my program.
I would contact the manufacturer, or wherever your purchased it, for recommendations or a guarantee.
At a previous place, our NIST Ref Thermometer was sent out yearly to be calibrated to NIST. We used it in a similar fashion to you with a +/- variance for the thermometers on the floor.
Hi everyone,
I have a question about my reference thermometer calibration frequency. last year I purchased a certified NIST thermometer to be used as a reference to verify the thermometers used in the production floor. The certificate of calibration has an issue date but not an expiation date. How often should I send it out for recalibration or get a new one?
I called Thermoworks and they told me they don't give an expiration date, just issue date
Hi Padfoot,
I assume yr query is audit XYZ oriented + no significant operational problems in the thermometers usage.
If audit requirements are unspecified, annual implementation is IMEX a usually acceptable response. Ideally the calibration results should be stated as NIST traceable.
We send our out yearly as well to be re-certified. It just helps to eliminate questions as annual seems to be widely acceptable. Anything more then we would be expected to provide justification.
I've always bought 2 thermometers. If you send one out to be calibrated what do you have on the production floor to test against? Same goes for check weights and most items listed on my calibration roster. A little of topic from the OP, but something I would look into before sending the only thermometer you have in to be calibrated.
I've always bought 2 thermometers. If you send one out to be calibrated what do you have on the production floor to test against? Same goes for check weights and most items listed on my calibration roster. A little of topic from the OP, but something I would look into before sending the only thermometer you have in to be calibrated.
We use the MiG thermometer to gauge 2 digital thermometers and 3 analog. We can tell which digital runs closest to the MiG and for the 3 weeks (approx.) that the MiG is out, we use that digital as a reference. Auditors in the past 10 years have had no issue with that.
We use the MiG thermometer to gauge 2 digital thermometers and 3 analog. We can tell which digital runs closest to the MiG and for the 3 weeks (approx.) that the MiG is out, we use that digital as a reference. Auditors in the past 10 years have had no issue with that.
In the end it depends on your process and your risk. I have never used a thermometer if it wasn't necessary. Depends on what your definition of "runs closest" is. Imagine your critical limit is 39* and your "run closest" says 39* but it is not accurate and your shipping product above 40*. 3 weeks is a lot of product that could be contaminated. Its might never be an issue with an auditor, but what will be the issue if "runs closest" turns to a recall? OP if your going down the road of buying 1 thermometer because you have assessed a risk that you need one, think of grabbing a second is all I am saying!
In the end it depends on your process and your risk. I have never used a thermometer if it wasn't necessary. Depends on what your definition of "runs closest" is. Imagine your critical limit is 39* and your "run closest" says 39* but it is not accurate and your shipping product above 40*. 3 weeks is a lot of product that could be contaminated. Its might never be an issue with an auditor, but what will be the issue if "runs closest" turns to a recall? OP if your going down the road of buying 1 thermometer because you have assessed a risk that you need one, think of grabbing a second is all I am saying!
Agreed! Our temperature checks are verification that our process (temp checks done by computer sensors) is accurate. This is not a CCP.
In the end it depends on your process and your risk. I have never used a thermometer if it wasn't necessary. Depends on what your definition of "runs closest" is. Imagine your critical limit is 39* and your "run closest" says 39* but it is not accurate and your shipping product above 40*. 3 weeks is a lot of product that could be contaminated. Its might never be an issue with an auditor, but what will be the issue if "runs closest" turns to a recall? OP if your going down the road of buying 1 thermometer because you have assessed a risk that you need one, think of grabbing a second is all I am saying!
Hi Tyler,
You appear to be a well-intentioned but Calibration pessimist. :smile:
Typically, the use of calibrated, sub-master, thermometers facilitates Production Control in the absence of the reference/master unit.
Hi Charles,
I always enjoy reading your posts on various topics. As I have grown with GFSI audits ( with knowledge growth of both SQF and BRC and numerous beatings by various auditors over the years) its hard to not be a pessimist. When somebody asks me what I do for work that has no knowledge about about food safety I always say I take the worst case scenarios and find a way to prepare for them to happen (Crisis Management) or to find a way to control them (CCP/CP). Not meaning to get this OT, but like I mentioned before its based on risk to each facility and how often they verify with a NIST thermometer. If you verify production thermometers once per shift or daily with a NIST traceable thermometer per your SOP from the conclusion of your RA then sending out your only one for weeks cannot be acceptable. If you verify monthly then no problem. I go all in on everything when building programs or otherwise what's the point, "typically" tells me its not 100 % :sofa1:
Hi Charles,
I always enjoy reading your posts on various topics. As I have grown with GFSI audits ( with knowledge growth of both SQF and BRC and numerous beatings by various auditors over the years) its hard to not be a pessimist. When somebody asks me what I do for work that has no knowledge about about food safety I always say I take the worst case scenarios and find a way to prepare for them to happen (Crisis Management) or to find a way to control them (CCP/CP). Not meaning to get this OT, but like I mentioned before its based on risk to each facility and how often they verify with a NIST thermometer. If you verify production thermometers once per shift or daily with a NIST traceable thermometer per your SOP from the conclusion of your RA then sending out your only one for weeks cannot be acceptable. If you verify monthly then no problem. I go all in on everything when building programs or otherwise what's the point, "typically" tells me its not 100 % :sofa1:
hi Tyler,
Thks comments.
I applaud yr dedication. :thumbup:
IMEX verification of roving thermocouples occurs monthly. Fortunately most of the risk-sensitive ones I've handled have been built in and tend to be of good stability. A more problematic example is cold room gauges around 6m up at -18degC in an air blast. Batteries and ears rapidly protest.
It's certainly true that organising/understanding the calibration documentaton for a wide scale thermometer can be a demanding exercise compared to buying a nice new, pre-calibrated one.