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Humidity Offset Option? **solved**
Posted: Sat Jun 06, 2015 5:48 am
by crazyace
Would it be possible to add a humidity Offset (correction) option in the local settings of the Select Station tab? Meteobridge allow correction options for temp, pressure, etc but I need the same for my Humidity values which I believe to be a little off on my sensor.
Re: Humidity Offset Option?
Posted: Sun Jun 07, 2015 12:36 am
by admin
you can do that be defining the range your humidity sensor is able to reach out to. Meteobridge then does stretching of your sensors data into the 0-100% range.
Re: Humidity Offset Option?
Posted: Sun Jun 07, 2015 7:23 am
by crazyace
Hello, thanks for the reply but I am not sure that the current humidity stretch option is exactly what I need. In my case my humidity sensor seems a little lower (drier) that other stations around me much of the time. I would like to be able to add a correction factor to my reading to increase the humidity a few percent. This is similar to adding a fixed amount to the pressure. Maybe I am misunderstanding but isn't the current humidity option to stretch low readings to 0% and high readings to 100%?
Re: Humidity Offset Option?
Posted: Sun Jun 07, 2015 2:03 pm
by admin
yes, when your sensor just covers 10% to 90%, then you can stretch it to 0% - 100% by linear interpolation.
When you just want to add 10% of humidity, set lower bound to -10 and upper bound to 90. This way
10 will be added to whatever the sensor reports as relative humidity, but values will be clipped in 0-100
range, of course. As you see, what Meteobridge has implemented does cover your request and offers
even more.
BTW: When you say "correction factor" I think you mean adding an offset, just to be precise as offset
and factor have a complete different meaning in math.
Re: Humidity Offset Option?
Posted: Sun Jun 07, 2015 7:52 pm
by crazyace
Yes, I mean an offset, but thanks for correcting me.

I don't think the ability to add the offset is very intuitive but I am glad that what I am requesting is possible. Appreciate the response.
Re: Humidity Offset Option?
Posted: Wed Jun 10, 2015 4:03 pm
by crazyace
I have experimented with the offset values that you suggested and it does not seem to make any change to my reported humidity values. I am using a secondary Acurite temp/humidity sensor which I have assigned as my outdoor sensor in the Live tab (I am not using the 5 in 1 humidity sensor). Is the change supposed to be instant or is there a delay that I should expect after I make the -10/90 humidity stretch change? For example, now I have 89% humidity and in reality the humidity is closer to 100%. After the changes my humidity is still 89%.
Re: Humidity Offset Option?
Posted: Sat Jul 04, 2015 3:08 am
by crazyace
Any update on my last post? I have experimented with the humidity offset as you instructed with no change. I would like to be able to add to my humidity value as my sensor appears to be a little low.
Re: Humidity Offset Option?
Posted: Sat Jul 04, 2015 8:42 am
by admin
I inserted offsets as shown below and it lifts the humidity values by 10%.
So it looks like it works exactly as I did describe. No idea what you are doing wrong.
Humidity before applying new setting:

- hum before.png (10.76 KiB) Viewed 4786 times
New setting:

- hum-offset.png (7.31 KiB) Viewed 4786 times
Humidity after applying new setting:

- hum-after.png (10.86 KiB) Viewed 4786 times
Of course, this only applies to the primary outdoor temp/hum sensor "th0".
Re: Humidity Offset Option? **solved**
Posted: Sat Jul 04, 2015 4:37 pm
by crazyace
Ok the issue appears to be due to me using a secondary temp/humidity sensor. I would like to apply the offset to the secondary sensor instead of the primary humidity sensor. Could this be an option to add in a future version?