TRM.42650--mimic temp of component stored

[teskridge]

"The temperature sensor probe should be in liquid ...and a volume similiar to the smallest unit stored." What are facilities doing for syringes being stored?

Thanks.

[Townsend]

Not a thing.

This checklist item is - "the temperature of refrigerators is monitored in a manner that will mimic the temperature characteristics of a component stored in the device."

We use 10% glycerol solution in a small bottle to mimic a small aliquot of blood. We give syringe aliquots a 4 hour outdate, so that's really not applicable.

Stephanie Townsend, MT(ASCP)SBB

[teskridge]

How much solution is in your bottle? Are you using the NIST certified thermometer bottles that you can buy?

Thanks for your help.

[Townsend]

Nope, they're just the good old plastic bottles with about 100-150ml of 10% glycerol solution. The thermometer and refrigerator probes are just inserted into the bottles.

[teskridge]

Thanks. Another question.....what kind of thermometer setup do you use to check your daily temperature of your blood storage refrigerator?

[Townsend]

It is just a regular spirit-filled thermometer which is placed in that bottle of glycerol. The thermometers are checked against an NIST-certified thermometer annually. Our double-door units have one thermometer/bottle on top and an additional on the opposite side, bottom shelf. The single-door units have only the one on top.

Is anyone doing this differently?

Stephanie Townsend, MT(ASCP)SBB

[teskridge]

Sorry, Stephanie...I don't think I've been very clear..I even confused myself, so I called CAP. I was told that a thermometer should be somewhere in the refrigerator (whether it is the sensor probe bottle, or the daily thermometer bottle) that has an amount of liquid in it that is equal to the least amount of product you would place in the refrigerator. Example: 20 mls of RBCs in a syringe.....then you would need a thermometer in 20 mls of liquid (10% glycerol) to mimic that volume.

[David Saikin]

I validate my probe thermometers with a NIST thermometer - (both upper and lower). Same with the probe in my freezer and water bath. I had an inspector tell me one time that these did not constitute thermometers - she was in error.