I bought two HimidiProbes recently, and used them for an experiment described below. But they both stopped working after a couple of runs.
We want to control the relative humidity of a small cylindrical container (14cm height, 4cm diameter) by saturated salt solutions. In this case potassium iodide and sodium bromide are used. The temperature is kept at a fixed point using a heating tape which is controlled by a PID controller. The heating process from room temperature to required temp of 60oC takes about 5min.
First couple of runs were ok for both of them. But the first probe broke after 5hr in 5th run. The second one broke after 3.5hr in 2nd run. The software showed bad readings such as negative temp and relative humidity.
So have you got any ideas why they stopped working?