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Electronics => Repair => Topic started by: duzycinek on November 05, 2022, 04:01:50 pm

Title: How to replace resistive humidity sensor on weather station
Post by: duzycinek on November 05, 2022, 04:01:50 pm
Hello, I got problem how to decide which humidity sensor should I buy for replacement in my weather station transmitter. I got N25FR wireless 433mhz weather station model WH1050 and it has resistive humidity sensor inside, which is faulty. It measures about 12-15% air humidity all the time. I was searching for replacement but noticed that almost every sensor is powered by VAC. After few measurments it seems my sensor is powered by 3VDC(2 AA series battery). Anyone have experience with stations like this and could advice which sensor replacement should I buy? Adding photos of sensor with module and measurments with osciloscope on both legs of sensor.
Title: Re: How to replace resistive humidity sensor on weather station
Post by: TheMG on November 05, 2022, 10:46:51 pm
Looks like a bog standard HR31/HR202 type sensor or similar.

By the way, it's capacitive not resistive.
Title: Re: How to replace resistive humidity sensor on weather station
Post by: duzycinek on November 06, 2022, 08:28:56 am
Yes, I noticed it also, but the problem is that these sensors should be powered with AC. It is not problem on this case? They also works with DC?

Quote from: TheMG on November 05, 2022, 10:46:51 pm
By the way, it's capacitive not resistive.
Yes, sorry, my bad.
Title: Re: How to replace resistive humidity sensor on weather station
Post by: duzycinek on December 12, 2022, 12:58:52 pm
Hello, if anyone was interested, it seems that is HR31 sensor. Readings are almost same as orginal one.
Title: Re: How to replace resistive humidity sensor on weather station
Post by: testpoint1 on December 15, 2022, 05:26:52 am
it is HR202L, 100% is resistance sensor, capacitor is different, I have much more in hand, if you in US, free one for you.
Title: Re: How to replace resistive humidity sensor on weather station
Post by: duzycinek on December 15, 2022, 10:46:49 pm
Thank you, sadly I am from europe :P