Author Topic: HOWTO: Adjust WeeWX when upgrading a Davis temp/humidity sensor  (Read 421 times)

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Offline noctilucent

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This is pretty straightforward but I figured I'd post it here to get it online and Google-able if someone else needs to do it: When replacing the temp/humidity sensor on a Davis weather station and going from an older 7346-166 (Sensiron SHT15) to the current 7346.070 (Sensiron SHT31), you need to add a temperature offset of -0.5C for the new sensor.  To do this:
Code: [Select]
sudo vi /etc/weewx/weewx.conf
/\[\[Correct
  outTemp = outTemp - 0.5
:x
sudo /etc/init.d/weewx restart
Keep an eye on whatever you're using to monitor the weather station stats and you'll see it jump by around 0.5C at the next update.

Offline mcrossley

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Re: HOWTO: Adjust WeeWX when upgrading a Davis temp/humidity sensor
« Reply #1 on: July 04, 2021, 12:03:27 PM »
You should make the adjustment in the station, then the console will read correctly - along with any other software like weewx that reads from it. It also means the dew point and wind chill will be calculated correctly.
Mark

Offline noctilucent

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Re: HOWTO: Adjust WeeWX when upgrading a Davis temp/humidity sensor
« Reply #2 on: July 05, 2021, 04:55:25 AM »
How do you make the adjustment in the station?  It's a sealed, non-user-adjustable device isn't it?

Offline johnd

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Re: HOWTO: Adjust WeeWX when upgrading a Davis temp/humidity sensor
« Reply #3 on: July 05, 2021, 07:23:35 AM »
Station = console + ISS (+ any supplementary transmitters/sensors). Offset adjustments are made to the console.

If you're not using a console, eg Weatherlink Live instead, then look at Advanced Settings in Device configuration on the browser interface online.
Prodata Weather Systems
Prodata's dedicated Davis EnviroMonitor website
UK Davis Premier Dealer - All Davis stations, accessories and spares
Cambridge UK

Sorry, but I have no time to help with individual issues by email. Please post your issue in the relevant forum section here & I will comment there if I have anything useful to add.

Offline noctilucent

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Re: HOWTO: Adjust WeeWX when upgrading a Davis temp/humidity sensor
« Reply #4 on: July 05, 2021, 07:25:50 AM »
I'm using an SDR to read data directly from the ISS, there's nothing between the ISS and WeeWX.

Offline johnd

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Re: HOWTO: Adjust WeeWX when upgrading a Davis temp/humidity sensor
« Reply #5 on: July 05, 2021, 07:29:15 AM »
I'm using an SDR to read data directly from the ISS, there's nothing between the ISS and WeeWX.

Fair enough - your solution obviously applies then. But anyone using a more conventional station set-up might find themselves making the temperature correction twice over.
Prodata Weather Systems
Prodata's dedicated Davis EnviroMonitor website
UK Davis Premier Dealer - All Davis stations, accessories and spares
Cambridge UK

Sorry, but I have no time to help with individual issues by email. Please post your issue in the relevant forum section here & I will comment there if I have anything useful to add.

Offline noctilucent

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Re: HOWTO: Adjust WeeWX when upgrading a Davis temp/humidity sensor
« Reply #6 on: July 05, 2021, 07:43:10 AM »
Fair enough - your solution obviously applies then. But anyone using a more conventional station set-up might find themselves making the temperature correction twice over.

Ah, good point, if you're already correcting via the ISS read process then don't correct a second time in WeeWX.