[Moderator's note: Recategorized thread to "Basic".] I'm having an issue at work that I think may be down to temperature. I have a sealed chamber that is 1m X 1m X 1.5m. The chamber has to be pressure tested but the results are all over the show. The only variable is temperature. So my question to you guys is can you calculate how temperature will effect the pressure? The pressure I'm trying to maintain in 200Pa. The temperature varies from 17'C to 22'C. How much does each 1'C effect that pressure if we are starting at 200Pa and 22'C? Any help would be very much appreciated.