On Fri, Jul 15, 2022 at 5:17 PM Tomas Kuchta <[email protected]> wrote: > > On Fri, Jul 15, 2022, 17:04 Russell Senior <[email protected]> > wrote: > > > I have used a bunch of these: > > > > https://www.amazon.com/gp/product/B00T0K8NXC/ > > and > > https://www.amazon.com/gp/product/B01G7BE9WK/ > > > > with https://github.com/merbanan/rtl_433 and an rtlsdr (like this: > > https://www.amazon.com/gp/product/B00VZ1AWQA/) to decode. > > > > For improved accuracy, I calibrated the sensors in an icebath (in > > several layers of ziplock bags and desiccant) for 0 degrees offset. > > . > > > These are good sensors with great battery life. I also have ThermPro > sensors, they work, but the ones Russell lists are better, smaller and much > longer battery life. > > I do not calibrate them. I care about being comfortable and saving power > rather than worry about whether the temperature reading is 0.2-0.3 degrees > different from absolutely correct value.
Fwiw, I didn't calibrate mine for a long time, but mine aren't so much for automated control, they were for understanding the temperature environments, and in particular differences and/or gradients in various microclimates. I noticed that a particular outside location seemed to get down to freezing before the other sensors. The significance of small temperature differences increases the closer you are to freezing, for example. Eventually, I just wanted to understand whether the difference was due to the sensor or the microenvironment it happened to be in. Unless vigorously stirred, there can be significant temperature differences over very short distances, due to heat sources, stratification, illumination, etc. I'd really like to have a lab grade temperature sensor, accurate to 0.01°C, to actually calibrate against. I encountered sensors when I worked in Oceanography with that kind of precision, but they were designed for water temperature and also were several thousand dollars. I wouldn't like to have one *that* much. Most consumer grade sensors only claim ±1°C. > > -T
