Got it, poorly expressed. I guess I was looking past the differential sensor test to the final objective of demonstrating reporting atmospheric pressure to an accuracy of 0.1mb.
Also, the pressure from home forced air handlers are measured in IWC, inches of water. atmospheric pressure is measured in inches of mercury. Big difference. Assuming your air handler has a return duct, the net interior pressure is a fraction of a inch of water. This is insignificant when compared to the pressure from 20 to 30 inches of mercury.Although the net interior pressure is very small is there not a potential issue with local pressure increases? Most systems that I have owned or seen have a single central return register. Surely there is a local variation in pressure in a closed, or semi-closed, room with only supply registers. After all the study is designed to support reporting to an accuracy of 0.1mb which is only 0.04 inches of water.
No correction needs to be made in the study to compensate for indoor/outdoor temperature differences.In the differential study I agree. My question relates to effect on the accuracy of the reported pressure of air which is heated or cooled vs the outdoor air (since we are considering a very precise measurement).
Nico, I'm curious if you own and operate a personal weather station that reports to NWS through CWOP?Own, yes, for many years, report to CWOP, no. I have an official airport station a couple of miles away. My data has always tracked has very closely with that station and I can't hope to compete with the accuracy of several $K of equipment with Davis equipment, so for geographical and technical reasons I don't see that sending it to CWOP would have any real value.