Temperature sensor with 0.1 precision? (EU)

What country are you in? The device selection does vary somewhat.

BATTERY POWERED AMBIENT TEMPERATURE SENSORS

In general, devices intended for the European or Asian market are more likely to offer temperature intervals of less than 1°. Even then, most of the ones in the price range that most smartthings customers are looking for only guarantee accuracy down to 0.5°C.

The Fibaro multisensor available on either the US or UK frequency is a good example. It can be set to report in intervals down to as low as 0.1°C, but it only guarantees accuracy down to 0.5°. The Sensative Comfort sensors are the same: they will report in 0.1°C intervals, but only guarantee accuracy of 0.5°

Probe sensors

There are some DS18B20 probe sensors which have a higher accuracy, quite often down to 0.01°C. These are not smart in themselves, you attach them physically to a smart device, probably most commonly a Fibaro RGBW controller which can handle up to four probe sensors. Or there’s a Qubino model that comes with its own probe. These are frequently used in gardening or aquaculture or brewing.

However, they usually aren’t good at just checking the ambient temperature in the air, as they get confused when the temperature is different on different sides of the probe. They are really designed for immersive applications like soil or water temperatures.

Mains powered sensors

You will generally get better accuracy from a mains powered sensor then from a battery powered sensor just because the battery powered sensors tend to try not to take too many readings in order to extend the battery life.

A community member has designed and built a plug-in zigbee sensor with excellent accuracy which has been very popular among community members who don’t require branded products and aren’t worried about childproofing or similar issues. I don’t think he has any for sale right now, but you could create your own version if you have strong technical skills, and it can also give you an idea of the difference in using Mains powered devices. you can read about it in the following thread:

Another Zigbee Repeater Solution (With Temperature, Humidity, Pressure and Light sensors)

Or you could use an Arduino and add high accuracy temperature sensors to it and then use the “ST_anything” project to report the values into smartthings. Again, that requires significant maker skills, but some community members are doing it.

[RELEASE] ST_Anything - Arduino/ESP8266/ESP32

There are some ready-made high accuracy mains power sensors, but they tend to be much more expensive than most smartthings customers want to use.

Summary

For for normal climate comfort control, adjusting room heating or cooling, you should find quite a few options that are battery powered, respond to the ambient air temperature, can report in intervals of 0.1°C but are only accurate up to 0.5°C.

You are more likely to find these in devices which are branded “multisensor“ rather than a “motion sensor“ that happens to have a temperature sensor as well. That’s just a matter of keeping costs down on the part of the manufacturer.

For use cases requiring greater accuracy that can use an immersed probe sensor, you should also find several options. Note that these are not usually good for measuring room temperature in the ambient air because the probe gets confused when temperatures are different on different sides of the probe itself.

If you really need better accuracy than 0.5°C for ambient temperature, you will probably have to go to a Mains powered device and may even have to build your own.

I hope that helps. :sunglasses:

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