Having your Temp measurements separate from your RH will be less useful to your Assessor than having a unit that correlates both measurements. This past spring I gave a C2C webinar on “Choosing the Datalogger that is Right for You”. You can view the talk and the associated Conserve O Gram in the C2C site at
If cost is your main factor there are three products that I’d recommend considering:
1. The Onset U12s are a solid product that has wide use in our field. The software is easy to use.
2. The LogTag loggers performed well on our accuracy tests, have nice software and is a good product at an extremely cheap price point
3. The Lascar EasyLog is also a decent logger, very small and cheap.
None of these will do what some of the higher end loggers (e.g. the PEM2 or ACRs will do) but they will get you data that your Assessor can have faith in.