topic Re: Sensors measurement precision in Rapid IoT

Sensors measurement precision

cerny — Wed, 24 Apr 2019 09:28:34 GMT

Hello Eric,

comparison to reference device located at the same place as Rapid IoT kit, five minutes after start of both devices, OOB demo app in Rapid IoT

KIT Reference

temperature : 27 25.22 C

humidity: 22 39 %rh

presure: 977 985 hPa

Main diference is humidity, about 50%, how to adjust it ?

Best Regards

Stanislav

Re: Sensors measurement precision

stephanie_m — Wed, 24 Apr 2019 15:23:21 GMT

Hello,

Are you having the same behavior on both kits? Is it always before that time? How are you getting the reference?

Regards,

Estephania

Re: Sensors measurement precision

frq05186 — Wed, 24 Apr 2019 15:23:26 GMT

Maybe your reference is wrong ?:smileyhappy:

Am joking - we know the sensor measurements into the kit are not accurate.

That's because the temperature and humidity measured are the ones into the package and are not reflecting 'ambient'

This is also true for air quality and light measurement by the way.

Air is not ciruclating properly into the kit (we wanted to keep it small to develop application)

Light is coming through a hole and is impacted by LEDs into the kit.

For the temperature, we removed an offset (7°) as the self heating (assuming the micro always run at max clock) is repeatable - you would notice a stabilization time assuming you plug a kit whose battery was depleted.

For humidity we did not take any compensation measure as we did not had a proper way to calibrate the humidity measurements vs reality.

Re: Sensors measurement precision

cerny — Fri, 03 May 2019 04:16:05 GMT

Thank you Eric, highly appreciated. Some ideas might be helpful for the better temperature adjustment, for instance use temperature measurement on other sensors built in kit or micro bus external devices, for example dust sensor from Maxim have 0.65 C precision temperature sensor as well and located out of MCU heating range, so I believe for our app we could manage temperature measurements also with such a benefit. Multiple sensors availability is also good for various adjustments and reference, would be nice to have such and demo app in Atmo for others. With our app we had limited time to dive in RapidIoT and I highly appreciate your support here, helped a lot! Thanks again!

Stanislav