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VP2 temp/humidity sensor issue

Discussion specific to Davis weather stations
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Mapantz
Posts: 979
Joined: Sat 17 Dec 2011 11:55 am
Weather Station: Davis Vantage Pro2
Operating System: Windows 10 x64
Location: Dorset - UK
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VP2 temp/humidity sensor issue

Post by Mapantz »

Hello

Is it possible for the humidity sensor to fail without affecting the temp part of it?

I noticed last night that my humidity levels were way off. It was thick fog here, my other station was showing 96% whilst the VP2 was at 61%.

I took it all apart this morning, and it was clean as a whistle. The debris screen was clear, both inside and out.
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freddie
Posts: 1330
Joined: Wed 08 Jun 2011 11:19 am
Weather Station: Davis Vantage Pro 2
Operating System: GNU/Linux Ubuntu 20.04 LXC
Location: Alcaston, Shropshire, UK
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Re: VP2 temp/humidity sensor issue

Post by freddie »

I've experienced the other way about (temp fails but humidity okay) twice in 14 years. So I guess theoretically the answer is yes.
Freddie
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Herbaldew
Posts: 103
Joined: Sun 12 Mar 2017 8:33 pm
Weather Station: VP2+
Operating System: Raspberry Pi OS (32-bit)
Location: US Mid-Atlantic

Re: VP2 temp/humidity sensor issue

Post by Herbaldew »

Yes. Mine did just and I replaced it about a month ago.

It failed by giving very low humidity readings. After reviewing my data logs, it looks like the humidity readings had been slowly drifting lower for many months.

It had been online for 4.5 years.

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mcrossley
Posts: 8473
Joined: Thu 07 Jan 2010 9:44 pm
Weather Station: Davis VP2/WLL
Operating System: Buster Lite rPi
Location: Wilmslow, Cheshire, UK
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Re: VP2 temp/humidity sensor issue

Post by mcrossley »

Humidity is usually the one to go, the readings get lower over time. If it has gone completely whacky then it's probably time to replace it, but...

I have had success reviving the low reading humidity sensor in the past - basically put it in electric (not gas!) oven.

Sensirion have the following recommendation for the reconditioning process...
Baking: 100 – 105°C at < 5%RH for 10h
Re-Hydration: 20 – 30°C at ~ 75%RH for 12h
I didn't leave in the oven for 10 hours, more like 2. Then left in the house to re-saturate for an afternoon. It was back to original performance after that.
(but not after I have bought a replacement! I have since repeated the process, swapping the sensors over to keep continuity of readings)

Mapantz
Posts: 979
Joined: Sat 17 Dec 2011 11:55 am
Weather Station: Davis Vantage Pro2
Operating System: Windows 10 x64
Location: Dorset - UK
Contact:

Re: VP2 temp/humidity sensor issue

Post by Mapantz »

It looks as though mine is on it's way out then?!

Currently reading 70%, while my other station is at 81%.

I did notice, that despite getting my station in 2016, I ended up with the older temp/humidity sensor. 07315.176C REV C0 2009

If I bought the newer 7346.070 would I need to add the 0.5°C offset? My ISS is AR151216047

With the amount of replacement items I have bought for this station, I could have bought a new VP2. :groan:
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Mapantz
Posts: 979
Joined: Sat 17 Dec 2011 11:55 am
Weather Station: Davis Vantage Pro2
Operating System: Windows 10 x64
Location: Dorset - UK
Contact:

Re: VP2 temp/humidity sensor issue

Post by Mapantz »

As the humidity outside goes up, the humidity on my station goes down. :lol:
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Mapantz
Posts: 979
Joined: Sat 17 Dec 2011 11:55 am
Weather Station: Davis Vantage Pro2
Operating System: Windows 10 x64
Location: Dorset - UK
Contact:

Re: VP2 temp/humidity sensor issue

Post by Mapantz »

New temp/humidity sensor installed. -0.5°C offset applied to console. All good.
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