Ok so in addition to the % possible error, a reading of 1.15 can be off by 0.05 or is it 0.01.
In other words, do we disregard the least significant digit altogether or just by one value?
Off by 0.05 would be +/-5 digits, Off by 0.01 would be +/- 1 digit (which I haven't seen at that resolution). Usually when you see +/- 1 digit the resolution is only 0.1, and would be equivalent to +/- 10 digits with a resolution of 0.01.
I have used the Testo Humidity stick, which I believe is the 605-H1. It looks exactly like the 605-H2, but it runs on AAA batteries. I believe the H2 runs on button cells. They may have changed due to poor battery cover performance. Mine has been draped in blue masking tape from day one to keep the batteries from popping out. After you are done being ticked off about the batteries and duct tape on your expensive new toy, it works pretty well.The H1 is compact and great for shoving in a grill or drilling a hole in a plenum and dropping in. My unit is dreadfully slow at registering temps, but I have no comparisons. If you stick it in a grill to get a temp, come back in 5 minutes.
I recently thought about buying a new unit as my old one is getting pretty ragged, but when I saw that the new ones were those infernal button cell batteries, I canceled the order. Anyone had any luck with the button cells on the new Testo?
I recently bought a Fieldpiece Humidity stick. Can't remember the model, but it is a pen sized unit that displays rh/wb/db. Runs on a single AA or AAA Cost was $66 and the display is very small. WB/DB are measured in full degrees, not tenths. In my opinion, it is the wet bulb equivalent of the fieldpiece pocketknife style thermometer; You are cursing while you're using it, but glad you have it over nothing.