Author Topic: The Reliability of the SHT-31 Humidity Sensor & What Psychrometer Should I Buy?  (Read 36442 times)

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Offline jgentry

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I talked to one of Davis’ tech folks. He forwarded my email to their design team regarding the suggestion of them switching the temp/hum sensor from the Sensirion SHT-31 to the IST HYT-221 sensor. He won’t be able to get a response from them but he did basically say that they may not switch due to compatibility issues and would have to redesign the transmitter board. But he wasn’t a 100% percent certain in which way they would go.

The Sensirion SHT-75 is the only option Davis users have if you live in an humid environment and want fairly reliable DP readings.
Davis Vantage Pro2. SHT-75. WU: KXALJEMI2 & KALTHORS2. CWOP/APRS: C6353 & E6358

  

Offline ValentineWeather

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Here are the specs:
 [ You are not allowed to view attachments ]

Randy

Offline galfert

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The required change is to go with an I2C bus and get rid of LSS. Then they can use any current and future sensor. This is inevitable and Davis will need to do this at some point.
WS-2000 & WS-2902A | Ecowitt GW1000 | WeatherBridge (Meteobridge)
WU: KFLWINTE111  |  PWSweather: KFLWINTE111
CWOP: FW3708  |  AWEKAS: 14814
Windy: pws-f075acbe
Weather Underground Issue Tracking
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Offline jgentry

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The required change is to go with an I2C bus and get rid of LSS. Then they can use any current and future sensor. This is inevitable and Davis will need to do this at some point.

Agreed. Hopefully they will do it very soon.  Unless there is a better option than the HYT-221, I hope they will use that sensor. Supposedly, it can handle very high humidity environments and is chemical resistant. According to IST, this sensor is good for agricultural use, which is one of Davis main targets for their stations.
Davis Vantage Pro2. SHT-75. WU: KXALJEMI2 & KALTHORS2. CWOP/APRS: C6353 & E6358

  

Offline jgentry

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Here are the specs:
 [ You are not allowed to view attachments ]

It would be interesting if the temperature sensor performs well during the winter in your location Randy.
Davis Vantage Pro2. SHT-75. WU: KXALJEMI2 & KALTHORS2. CWOP/APRS: C6353 & E6358

  

Offline ValentineWeather

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Here are the specs:
 [ You are not allowed to view attachments ]

It would be interesting if the temperature sensor performs well during the winter in your location Randy.

Looks about the same as SHT15 and 75. Not as good as 31 which is basic flatline through those sub-zero temperatures.
Randy

Offline WheatonRon

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The required change is to go with an I2C bus and get rid of LSS. Then they can use any current and future sensor. This is inevitable and Davis will need to do this at some point.

Inevitable like a color screen on its console, and wifi built-in?

Sorry, but I couldn’t resist poking fun at Davis, again, and its horribly dated technology.
« Last Edit: May 21, 2019, 04:08:38 PM by WheatonRon »
Davis VP2 with SHT31 (3 complete VP2 systems—2 with a daytime fan and 1 that has a 24 hour fan); CWOP--CW5020, FW3075 and FW4350; WU--KILWHEAT17, KILWHEAT36 and KILWHEAT39; WeatherCloud.net; CoCoRaHS--IL-DP-132; and Weatherlink 2.0

Offline Old Tele man

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The required change is to go with an I2C bus and get rid of LSS. Then they can use any current and future sensor. This is inevitable and Davis will need to do this at some point.

Inevitable like a color screen on its console, and wifi built-in?

Sorry, but I couldn’t resist poking fun at Davis, again, and its horribly dated technology.

The "Don't FIX what ain't BROKEN" adage taken to extreme?
• SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
• DBX2 & DBX1 Precision Digital Barographs
• CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
• WU - KAZTUCSO202, Countryside

Offline CW2274

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The required change is to go with an I2C bus and get rid of LSS. Then they can use any current and future sensor. This is inevitable and Davis will need to do this at some point.

Inevitable like a color screen on its console, and wifi built-in?

Sorry, but I couldn’t resist poking fun at Davis, again, and its horribly dated technology.
Ahhh yes, but yet you proudly display owning three of them... :-P

Offline WheatonRon

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The required change is to go with an I2C bus and get rid of LSS. Then they can use any current and future sensor. This is inevitable and Davis will need to do this at some point.

Inevitable like a color screen on its console, and wifi built-in?

Sorry, but I couldn’t resist poking fun at Davis, again, and its horribly dated technology.
Ahhh yes, but yet you proudly display owning three of them... :-P

Unfortunately, there isn’t a better system on the market at the Davis price point.
Davis VP2 with SHT31 (3 complete VP2 systems—2 with a daytime fan and 1 that has a 24 hour fan); CWOP--CW5020, FW3075 and FW4350; WU--KILWHEAT17, KILWHEAT36 and KILWHEAT39; WeatherCloud.net; CoCoRaHS--IL-DP-132; and Weatherlink 2.0

Offline galfert

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The required change is to go with an I2C bus and get rid of LSS. Then they can use any current and future sensor. This is inevitable and Davis will need to do this at some point.

Inevitable like a color screen on its console, and wifi built-in?

Sorry, but I couldn’t resist poking fun at Davis, again, and its horribly dated technology.

With the release of the WLL the color console with WiFi solution no longer needs to come from Davis. All we need now is for someone to come up with an app that mimics a display console. A cheap tablet is all you'll need and you are all set. We'll see that soon from some 3rd party developer.

Since the WLL release, for me this I2C bus support is the last remaining advancement into having something worthy of being called a VP3. Then I can have a new ISS with I2C sensors, a WLL that is the console to receive sensor data and 3rd party software to do what you want with the data (as Meteobridge is already supporting via WLL API), and soon the tablet display app utilizing the same WLL API that Meteobridge is using and you got yourself a VP3.
« Last Edit: May 21, 2019, 04:51:02 PM by galfert »
WS-2000 & WS-2902A | Ecowitt GW1000 | WeatherBridge (Meteobridge)
WU: KFLWINTE111  |  PWSweather: KFLWINTE111
CWOP: FW3708  |  AWEKAS: 14814
Windy: pws-f075acbe
Weather Underground Issue Tracking
Tele-Pole flag pole not up yet

Offline jgentry

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Here is a interesting video that briefly talks about the IST HYT sensors
https://youtu.be/X9vW5JroqE4
Davis Vantage Pro2. SHT-75. WU: KXALJEMI2 & KALTHORS2. CWOP/APRS: C6353 & E6358

  

 

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