Thermal Mapping Concepts - Drug store with dimensions 75m x25m x13m

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Mohammed Gouda

Dear friends,
i am confused about the thermal mapping .....
i want to learn more about themal mapping and validation of test spaces...

the main question is:"can i ues 2 diffrent systems in data logging in the same test?"and what is the evidence on that?"

ex:i made a thermal mapping for a drug store with dimensions 75m x25m x13m....and i used two systems,one of them is 10 thermocouples type "T" with a scanner...and the second one was data loggers with temp. sensor Pt-100,is the mixing between these two systems applicable or not??:bonk:
*notice that both systems were calibrated.
please send me your openions to can understand the correct concept in thermal validation...
 
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Hershal

Metrologist-Auditor
Trusted Information Resource
Re: Thermal mapping concepts

the two systems can compliment each other. The uncertainty is lower on the PT-100, but then the "T" thermocouples can be used as support for those results.
 
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Mohammed Gouda

Re: Thermal mapping concepts

so...there is no problem from usage of two systems...

but if i have only a few data loggers with PT-100 sensor,what is the best locations (configuration) that i can exploit the low uncertainity of them ??
 

Hershal

Metrologist-Auditor
Trusted Information Resource
You may have to tak muliple efforts, for example one day at one end, high-middle-low, then the center, then the other end.

It will take longer but that may be what you have to do with limited amounts of PT-100's.
 
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alex.Kennedy

The following letter was drafted for an existing customer of ours in Egypt, it answers some of your questions.


This is largely common sense.
You are required to validate the temperature that the product is subjected to, so you are only interested in the product storage areas. Hot air stratifies – heat goes up – cold goes down – so you want the two worst cases – top and bottom.
Examine the air flows around the warehouse, where air is exiting is not usually a problem. Where air is entering – is it affecting the warehouse temperature? Is it a permanent condition that requires verification, or is it a short term aberration?
For a standard 30m by 30m by 8m (100 x 100 x 25 feet) warehouse or store, with a standard temperature requirement of eighteen degree centigrade plus or minus six, I would consider the following adequate;

Where the following location are given it actually means - the nearest product storage point to.
Top shelf & bottom shelf – in each corner of the warehouse
Top shelf & bottom shelf – in the middle of the warehouse external walls.
Top shelf & bottom shelf – in the centre of the warehouse.

This gives eighteen recording points which would be adequate for this size of building. Areas around permanent inflows would have to be defined and addition sensors set to verify how this flow was affecting (the local) shelf temperature.

Shelf areas out with specified temperature, should be painted red and placarded ‘NOT TO BE USED FOR REGULATORY CONTROLLED PRODUCT.’ (this is not legislation, but we have done it often, and visiting regulators have always accepted it).
What ever you do, ensure it is document and warehouse staff, are trained accordingly. Also made certain it appears in their training records.

The type of sensor is completely irrelevant, just as long as its calibration is current and traceable to national standards (USA – NIST & UK UKAS). What governs the sensing system you use is the temperature range your product requires. For instance, if you have an extremely critical product, that required a storage temperature of twenty degrees centigrade, plus or minus one degree. You would require the mapping system to be one factor more accurate, i.e. accurate to plus or minus zero point one, of a degree. In reality a temperature range like this would be unworkable in the typical warehouse.

In practice whatever your storage temperature range is, there will be a tolerance and your mapping system has to be a one factor more accurate. I.e. a set point of twenty degrees centigrade plus or minus four degrees, would require a mapping system accuracy better than plus or minus zero point eight degrees.
(This takes account of all uncertainties, basic FDA accuracy repeatability requirement is one to four).

For ease of use the easiest to use by an enormous margin is the self contained data logger. Eighteen of these in a warehouse will hardly be noticed; there is no wiring and minimal interference with warehouse operations.

Just do an initial reference calibration by subjecting them all (along with a precision calibrated temperature indicator) to a temperature above and then below the range you expect to use, and documenting any error between their readings and that of the calibrated indicator. At the end of the testing, repeat this simple check calibration, and it become your ‘pre’ and ‘post’ check that all your sensors were correct, before and are still correct, after your mapping task.

The mapping should be carried out during the extremes of local environmental conditions, which usually equates to mid summer and mid winter. If you are mapping humidity you must verify that the system being qualified can cope with the full range of ambient conditions. For this reason the PQ has to be executed in phases, in order to demonstrate that the internal warehouse conditions can be maintained regardless of the seasonal variations in the local climate.

You can in general apply these fundamentals to all hot and cold storage or processing enclosures.

Alex Kennedy
 
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Mohammed Gouda

is there any references or SOPs for this ???

i have only 1 reference but i want a standards for validation....

"C[1].C.Chan, et al - Analytical Method Validation and Instrument Performance

Verification"........
 
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Talaat

Dear Mohammad Gouda,

Finally please send to me as soon as possible all document or data base related in this subject specific on the the using of the measuring different systems in the thermal mapping.

Talaat
 
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Mohammed Gouda

Dear dr. Talaat..

ok,i will call you
 
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