Hi Kumar –

Thanks for the question.

Your chamber has a volume of 19.28 cubic meters. Thankfully, this falls just under 20 cubic meters. This means you can use the guidelines presented in the ISPE’s Good Practice Guides on Cold Chain Management, and Controlled Temperature Chambers Mapping and Monitoring. In these guidance documents, they recommend starting with 15 sensors. One in each corner (8 probes), one in the geometric center (1 probe), and one in the center of each plane or side of the chamber (6 more probes). In addition to these 15 probes, you would want to add a few extra at points of interest, such as the controller probe, display probe, or monitoring probe.

As an alternative, you could follow the guidance of the WHO. They will tell you to put a stack of three (low, middle, and high) in each corner (12 probes to start), and then a distribution of additional sensors in high-risk areas – by the door, near the output of the HVAC system, on other shelves within the space. This will end up being close to 20 probes.

So, either by following the methodologies of either the ISPE or the WHO, you will need between 15 and 20 sensors to properly map a room or chamber of just under 20 cubic meters of volume.

Please be sure to document your probe locations and your rationale for your choices.

Best Regards,
Paul Daniel
Sr. GxP Regulatory Expert