New RuuviTag 37F low

Ruuvi products 🇬🇧 RuuviTag & RuuviTag Pro sensors
1

Folks,

Brand new RuuviTag. Placed in freezer and reads -42, freezer itself says it is at -4. Took it out of freezer and it reads 31F, thermostat says 67F. It is reading a massive 36 to 38 degrees low! Any thoughts? Using a victron system to read the Tag. Dont want to install the 4 others I bought until I sort this out.

TIA

Andy

2

Have you read the tag via mobile app?

3

No, I used the Victron app. I will try that next. Seems that after a period of time the device at room temperature is slowly coming up to a more reasonable temperature. I am going to observe this over a period of time, and drag out a good thermocouple measurement.

Thanks

Andy

4

Is this the “pro” model with the black case?

It has a much longer tau than the “normal” ruuvi.

Have you tried removing the board from the case?

tau : Time Constant: Used in engineering and physics to indicate the time it takes a system to reach (roughly 63.2%) of its total step response

5

It is the basic one, not the pro. I understand tau. I am a little disappointed that Ruuvi doesnt publish any real data on the lag, accuracy etc of these devices, or any kind of data sheet on each item. I would hope that each of these had a basic check of two or three temps in the range. There is the variance of the Bosch(?) chip as well as the other components on the little board. Oh well

6

Perhaps this might help https://mybeacons.info/packetFormats.html#shtc3

or this

https://github.com/ruuvi/ruuvitag_fw/wiki

7

Hi @AndyRonLI ,

Thanks for your message and sorry for troubles with your RuuviTag.

The first thing that comes to my mind when reading this is to check with Ruuvi Station app first. If the readings are wildly different, then there is possibly an issue with software.

As @dgerman wrote, when using any sensor, including RuuviTag, there is a specific adjustment period while the sensor adapts to the surrounding environmental conditions We explain this in more detail in our support article here: Sensor Step Time or Sensor Measurement Delay - Ruuvi

The technical spec for RuuviTag sensors can be found here: https://ruuvi.com/i/u/ruuvitag-tech-spec-2023-04.pdf

Let us know by writing to support@ruuvi.com if your measurements are still not showing any sensible data and we’ll help you out.