Author Topic: 3 different OS products all show different humidity  (Read 3238 times)

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Offline doublecheese

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3 different OS products all show different humidity
« on: January 04, 2010, 08:14:59 AM »
Hi Guys

I have the following OS products.

a) OS WMR200
b) OS BTHR968 Sensor - humidity, barometer, temperature
c) OS THGR800 Sensor - humidiy, temperature

My problem is that all my sensors Humidity readings are different than each other eventhough they are now placed in the same place.

For example if we take today as an example. All sensor are in the same room .
The temperature is shown almost same in each sensor but when it comes to humidity I get the following results. Here is a sample of actual reading a few minutes ago all placed in the same room close to each other.

a) OS WMR200 - 46% Humidity
b) OS BTHR968 Sensor - 54% Humidity
c) OS THGR800 Sensor - 66% Humidity

Can somebody enlighten me how to calibrate these sensors to read all of them the same or similar results ?

Thanks

DC

Offline mackbig

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Re: 3 different OS products all show different humidity
« Reply #1 on: January 04, 2010, 09:00:34 AM »
Do you have any analog gauges you could check against.  Hard to tell which one is correct or close.

I have never heard of any issues with the BTHR968 (the thgr968 yes..)  I have a 4 year old one, and at any given time 3 Thgr268's around the house.  When put together they all measure within a few percentage points for humidity, and with a degree for temp.  I have only had one thgr268 go, and it was 7 years old (radio shack version), and the thgr968 that went for me was selt inflicted, the sensor flipped over and filled up with water during a 2 second install I did when moving)

Andrew

Andrew - Davis VP2+ 6163, serial weatherlink, wireless anemometer, running Weather Display.  Boltek PCI Stormtracker, Astrogenic Nexstorm, Strikestar - UNI, CWOP CW8618, GrLevel3, (Station 2 OS WMR968, VWS 13.01p09), Windows 7-64

Offline doublecheese

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Re: 3 different OS products all show different humidity
« Reply #2 on: January 04, 2010, 09:36:01 AM »
I can go and buy an anologue hygrometer as well.

Analogue hygrometers are somehow calibrated with a wet towel wrapped around them . Can I try the same with my digital sensors ?

The thing is even if buy an analogue hygrometer, how would I calibrate the digital ones ?
Is there a method for this that might work out ?


Offline mackbig

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Re: 3 different OS products all show different humidity
« Reply #3 on: January 04, 2010, 11:39:59 AM »
There is no way to calibrate them. My point of getting an analog (or two) to compare was so that you would know which digital ones to toss (or ignore).

Andrew

Andrew - Davis VP2+ 6163, serial weatherlink, wireless anemometer, running Weather Display.  Boltek PCI Stormtracker, Astrogenic Nexstorm, Strikestar - UNI, CWOP CW8618, GrLevel3, (Station 2 OS WMR968, VWS 13.01p09), Windows 7-64

Offline stevebrtx

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Re: 3 different OS products all show different humidity
« Reply #4 on: January 04, 2010, 12:53:28 PM »
No experience with the 968, but the 200 is junk, is sitting on the shelf behind me collecting dust. The 800 is 4 years old and agrees exactly with another OS relabeled Radio Shack and the WMR100 I recently retired. I've got a new 800 on the way as sensor #2 specifically for humidity, we'll see how it compares.

Offline DaculaWeather

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Re: 3 different OS products all show different humidity
« Reply #5 on: January 04, 2010, 03:23:32 PM »
My WRM100 is on the shelf too, things started going haywire and I couldn't take it anymore. Mine wasn't so much barometer as much as it was temp and humidity.

Offline doublecheese

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Re: 3 different OS products all show different humidity
« Reply #6 on: January 05, 2010, 03:18:34 AM »
Yesterday , I resetted all my devices and kept them all in the same place.

WMR200 and THGR800 are showing the exact percentage of humidity figures, but the BTHR968 shows about 10% more all the time.

I think the best is to check it with an anologue one and then decide what to do ....

After reading your posts I begin to think Davis makes better products than Oregon Scientific right ?

Offline mackbig

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Re: 3 different OS products all show different humidity
« Reply #7 on: January 05, 2010, 06:22:44 AM »
Yes, but you get what you pay for.  Happy with my Davis (aside from recent - - - issues), but also quite happy with my 3 extra sensors on my OS  wmr-968

Andrew

After reading your posts I begin to think Davis makes better products than Oregon Scientific right ?

Andrew - Davis VP2+ 6163, serial weatherlink, wireless anemometer, running Weather Display.  Boltek PCI Stormtracker, Astrogenic Nexstorm, Strikestar - UNI, CWOP CW8618, GrLevel3, (Station 2 OS WMR968, VWS 13.01p09), Windows 7-64

Offline DaculaWeather

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Re: 3 different OS products all show different humidity
« Reply #8 on: January 05, 2010, 06:36:27 AM »
I think Davis equipment is more accurate, it appears that it is also more reliable, time will tell for me. I had my WMR100 for almost two years before it crapped out, but it still wasn't that accurate before that.

Offline doublecheese

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Re: 3 different OS products all show different humidity
« Reply #9 on: January 05, 2010, 07:15:50 AM »
I'am now wishing for a windows based, LCD Touch Screen Weather Station with wifi which should be fully customisable according to user's needs...

Preferably Oregon Scientific as all my sensors are OS,,, if not Davis :) If such a model comes out I'll be first one to buy :)


Offline stevebrtx

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Re: 3 different OS products all show different humidity
« Reply #10 on: January 05, 2010, 09:36:49 AM »
As noted on several of my tirades, the new 200 is now relegated to being a data logger, the 100 console is back online, the 200 anemometer seems ok, the temp is an old 800 sensor and the rain gauge is what it is. Each morning I dump the data logger and one day when the power goes out I'll download and marry in the db, until then it's mostly a fancy (and expensive) data logger, the "I want a Davis" savings jar has already been primed with a few pesos.