Instruments Required for Cold Room/Freezer calibration

Please let me know the basic instruments along with all technical details for ColRoom/Deep freezer calibration .

Sayan,

Do you have temperature probes within the cold room/freezer? I assume you are looking at the calibration of the temperature monitoring equipment for these areas, in which case can the probes be removed for calibration, or in some cases they can be calibrated in situ by the supplying company or associates.

If there are no probes in the areas to continuously monitor the temperature there must be a means of establishing the temperature on a frequent basis, in which case these units need to be calibrated such as a probe being sent to an accredited site.

It would be useful to get a better picture of what you have and how you monitor the areas currently.

Yes we have probe and digital meter also.

For auditing purpose we hv to calibrate the same for every 3 months.This time we are willing to do inhouse.dats I am asking for the method and instrument details so we can do the same.

Hi sayan.cts,

I assume –

(1) target temperature around -18degC.

(2) there is a temperature measuring instrument (X) installed in an approx. warmest location in the room. Hopefully not in the roof.

(3) X has a visible display (typically external to the room).

(4) the location of the active measuring portion of X  is (approx.) known and (approx.) accessible.

Some temperature loggers  I believe are self-calibrating. I presume you do not have such a device.

Fix a small thermocouple probe, Z, for example of  short needle shape, in close proximity/contact to the active measuring  point of X. For example use electrical tape. For convenience Z should be matched to its own commercial display unit (it is possible to make one’s own “point” TCs and calibrate them but some expertise is required). The length of connecting lead between Z and its display unit should not be "excessively" long.

The probe Z will require to be previously calibrated either (a) by a company whose calibration equipment is traceable, for example to NIST, or (b) from a “master” unit which itself has been calibrated as per (a). If (b), the procedure can be in-house and duplicate that being currently described. The specific calibration temperature (or temperatures) will depend on your usage. As per (1) above the calibration would be at -18degC, this would likely to be ok for temperatures around  -15 to -20 degC  (guesstimate).

For routine use, IMEX, an agreement within 1degC is usually acceptable. Otherwise adjust the observed reading accordingly.