All posts in Calibration

Data from OSBSS proximity sensor

Now that our new proximity data logger tutorial is published, I would like to show some data of its performance. Below are photos from a co-location test with the initial prototype OSBSS proximity sensor and an off-the-shelf Onset HOBO occupancy/light logger in our lab. In our first test we simply launched both sensors with default settings and placed them side-by-side on the desk of a graduate student to record occupancy over a period of about 15 hours (we’re watching you, Parham!).

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Data from custom T/RH data logger – 1st build (revision 09 30 2014)


Two months ago I wrote a blog post documenting my first OSBSS build of our low power (long battery life) air temperature and relative humidity data logger. At that time we were using the SHT15 sensor breakout board to measure both temperature and relative humidity. After some co-location tests with Onset HOBO data loggers and others, we discovered that (a) yes we could achieve low power draw and long battery life on this base framework of a data logger, (b) yes we could achieve accurate relative humidity readings compared to a HOBO, but (c) unfortunately, our temperature readings were not very accurate (they were decent after calibration, but who wants to build a temperature sensor that then has to be calibrated against another, better temperature sensor!?). This last part really bugged us — we simply couldn’t rely on the SHT15 to provide accurate temperature measurements, which then, because RH is based on temperature readings, yielded both inaccurate T and RH readings.

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