[billnotgatez]

Has anyone used one of these devices?

http://www.hobodepot.com/labs/finished_labs/6343_hessslaw.html

[Donaldson Tan]

I used data loggers before, but they are not of the brand HOBO.

Data loggers are just 'glorified' measurement devices. The one in your link is a glorified thermometer.

The measurement data is transmitted to a PC which does the analysis. (eg. plotting graph)