For temperature logging only, I recommend "iButtons", very discrete miniature loggers which can be used not only in occupied spaces but also on heating pipework (for example) to find out what is running when. You can get a starter kit (including one iButton logger
and PC connectivity hardware and software) from
Embedded Systems. They also
sell additional iButton loggers: get part number DS1921G for temperatures up to 85°C or the more expensive
DS1922T if you need to get up to 125°C.
|Cheaper models are calibrated for incandescent light only, so their results are only approximate; more expensive models can be switched to compensate for the different characteristics of fluorescent light and daylight. The illustrated model costs about £30 but searching for a supplier today (16 Jul 08) I found it for £22 at www.digital-meters.com.|