Checking thermometers that are Guaranteed Accurate for Life

So the testing thermometers we use for determining final temps, maintaining temps, and tracking our cooling process are "Guaranteed Accurate for Life" and come with the claim "there is no need of field adjusting of calibration settings and no risk of introducing error into the instrument." In fact, there does not seem to be a way to calibrate them. They are NSF, CE, WEEE, RoHS certified.

Does this mean for these instruments I only need to periodically check and record their accuracy, but don't need to maintain a calibration log?

Thoughts?

Trust and Verify.

So the testing thermometers we use for determining final temps, maintaining temps, and tracking our cooling process are "Guaranteed Accurate for Life" and come with the claim "there is no need of field adjusting of calibration settings and no risk of introducing error into the instrument." In fact, there does not seem to be a way to calibrate them. They are NSF, CE, WEEE, RoHS certified.

 

Does this mean for these instruments I only need to periodically check and record their accuracy, but don't need to maintain a calibration log?

 

Thoughts?

Do these come with a certificate stating as such?  If so, then yes periodically check them for accuracy is all that is needed.

I would still use a log of some description. The paper trail is important to an auditor---and you could have always received a lemon of a thermometre

So the testing thermometers we use for determining final temps, maintaining temps, and tracking our cooling process are "Guaranteed Accurate for Life" and come with the claim "there is no need of field adjusting of calibration settings and no risk of introducing error into the instrument." In fact, there does not seem to be a way to calibrate them. They are NSF, CE, WEEE, RoHS certified.

 

Does this mean for these instruments I only need to periodically check and record their accuracy, but don't need to maintain a calibration log?

 

Thoughts?

Is this a glass mercury thermometer ?

I would be interested to see the actual documentation under discussion.

For one thing, what is the intended scientific meaning of the term "Accurate for Life" ? eg "error" not exceeding +/- 0.01degC over the temperature range -30degC - 200degC ? (forever ?)

I rather doubt that organisations like NSF interpret their "certification" as validating that the associated  instrument is "Guaranteed Accurate for Life".?

Same as above. As an auditor I would also say "So guaranteed for life provided the thermometer is always used between it's min/max, and is never damaged or handled improperly, how do you verify that's the case?"

Hi,

I agree with Charles C.. Nobody can give life long garantuee without setting disclaimers. Do you know this? Who somebody should know which improper handling occurs in this time? Regular verification vs a certified thermometer is in my opinion always necessary.

Rgds

moskito

If you do not verify your thermometers, you are setting yourself up for failure. At some point, everything breaks. If the battery does not have enough current, will it read low/high?

If one is out of calibration, the thermometer company will reimburse you for the cost of the thermometer, not any product you lose.

You alone are responsible for your SQF Program. 

We verify/calibrate our thermometers on a daily basis. That way if one is out of calibration, we only have 1 day of production to check.

If the thermometer is used for a CCP or something important to the safety of the product such as monitoring thawing temperatures or verifying temperatures of incoming perishable goods then I strongly suggest you verify the thermometer is properly working at the start and end of each shift and document this.  I say at the end of the shift too because things can change overnight so if you can prove the thermometer was good at the end of the shift then you know that day if the product is good. 

As broncobill indicated, nothing lasts forever, and if you find a thermometer was not working properly then all product would be affected back to the last time it was documented that the thermometer was verified to be in calibration.

All brilliant answers.

I would also read the small print.  "Guaranteed for life" may mean "when it breaks we'll replace it for free!"  Calibration needs to be traceable to a standard and can be simple.  If you can compare these thermometers to one calibrated to a national standard on a periodic basis and these continue to be within whatever tolerance you accept, then that's a perfectly acceptable "calibration" of that thermometer (strictly speaking I suppose it's a verification but the terms are interchanged on this kind of thing regularly and if it was out of spec, you're unlikely to be able to adjust it which is the calibration bit and presumably you'd be asking for that replacement...)

I would be curious to know who was making this claim?  Also whether it would stand up to being used as a tool to open plastic tubs (seen in one factory which shall remain nameless as a probe bent at a 90o angle was returned) or hitting a stirring paddle (same factory...) :shutup: