We use a humidity / temperature monitor from the PCE Group, Model PCE-HT110. It logs both temperature and humidity on an ongoing basis at regular intervals. The measurements are stored on an SD card which allows one to download the data to a spreadsheet for reference. Prior to receiving the unit, PCE sent it to a certified calibration service to ensure the unit was recording accurately. This has been very helpful to our work. A bonus is, by having the unit mounted on the job site, everyone is constantly reminded of the environmental conditions and can correct as necessary.
