Hi Renuka. For mapping, you can follow the ISPE guidelines found in their Good Practice Guide: Controlled Temperature Chambers Mapping and Monitoring. Your space is over 2 cubic meters, so that would indicate that you use 15 probes for temperature mapping. However, since it is a “walk-in” it sounds like all the space is not being used for storage/stability. Stability testing is a critical process, so I would start with 15 probes as a starting number for temperature mapping. Your mapping data will identify the hot and cold spots. But remember, as I mentioned in the blog, these are not critical as monitoring locations. Your mapping and validation of the chamber, if successful, will have proven that your stability chamber operates as expected, and it capable of maintaining the required conditions. That means that you don’t need to monitor both the hot and cold spot. You just need to take them into consideration. For monitoring, you should be fine with a single probe. If this seems insufficient, or your organization interprets the guidance as requiring monitoring at both the hot and cold spots, you can simply add a second probe. Any more than that would be overkill. In the blog, the asker of the original question was worried about having 4 spots to monitor, as they were worried about hi/lows in both temperature and relative humidity. This is usually a non-concern, as relative humidity extremes tend to show up in the same places as temperature extremes, as relative humidity is “relative” to temperature.
Best Regards,
Paul Daniel