Topic: SHT31

[drew1021]

I wonder if the SHT35 has been tried with the VP2 by anyone? Yeah I know, I'm an accuracy nut for sure.

[Old Tele man]

I wonder if the SHT35 has been tried with the VP2 by anyone? Yeah I know, I'm an accuracy nut for sure.

That's like trying to run APPLE on a PC -- Yeah, they're both computers just using ONE's and ZERO's, but they "speak" different communication protocols. The SHT35 uses a newer I2C serial communication format than the VP2 ISS has.

DATASHEET: https://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/2_Humidity_Sensors/Sensirion_Humidity_Sensors_SHT3x_Datasheet_digital.pdf

[drew1021]

I wonder if the SHT35 has been tried with the VP2 by anyone? Yeah I know, I'm an accuracy nut for sure.

That's like trying to run APPLE on a PC -- Yeah, they're both computers just using ONE's and ZERO's, but they "speak" different communication protocols. The SHT35 uses a newer I2C serial communication format than the VP2 ISS has.

DATASHEET: https://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/2_Humidity_Sensors/Sensirion_Humidity_Sensors_SHT3x_Datasheet_digital.pdf

Makes one wonder if Davis will ever try for better accuracy. Guess it depends on whether Sensiron comes out with a more accurate sensor with a compatible communication protocol.
Thanks for informing me on the subject.

[WxLover16]

I wonder if the SHT35 has been tried with the VP2 by anyone? Yeah I know, I'm an accuracy nut for sure.

When it comes to temperature/humidity, I think I might just take the cake for accuracy nuts. 

[dalecoy]

I wonder if the SHT35 has been tried with the VP2 by anyone? Yeah I know, I'm an accuracy nut for sure.

When it comes to temperature/humidity, I think I might just take the cake for accuracy nuts. 

Do you consider
     Accuracy to be the most important factor; or
     Precision to be the most important factor; or
     Resolution to be the most important factor?

[Old Tele man]

Pick one...

[WxLover16]

I wonder if the SHT35 has been tried with the VP2 by anyone? Yeah I know, I'm an accuracy nut for sure.

When it comes to temperature/humidity, I think I might just take the cake for accuracy nuts. 

Do you consider
     Accuracy to be the most important factor; or
     Precision to be the most important factor; or
     Resolution to be the most important factor?

Am I allowed to pick the option of all of the above, cause they're all important to me; not sure I can rule one out as lesser importance.

[CW2274]

I wonder if the SHT35 has been tried with the VP2 by anyone? Yeah I know, I'm an accuracy nut for sure.

When it comes to temperature/humidity, I think I might just take the cake for accuracy nuts. 

Do you consider
     Accuracy to be the most important factor; or
     Precision to be the most important factor; or
     Resolution to be the most important factor?

In this instance, how is it relevant? What could one change?

[dalecoy]

I wonder if the SHT35 has been tried with the VP2 by anyone? Yeah I know, I'm an accuracy nut for sure.

When it comes to temperature/humidity, I think I might just take the cake for accuracy nuts. 

Do you consider
     Accuracy to be the most important factor; or
     Precision to be the most important factor; or
     Resolution to be the most important factor?

Am I allowed to pick the option of all of the above, cause they're all important to me; not sure I can rule one out as lesser importance.

It's relevant because accuracy is not the only factor.  And there are often tradeoffs between the factors, in both the making of the sensors, and in how they are "read" by the system.

WxLover16, you are not allowed to pick "all of the above".  You (and Drew1021) said you are accuracy nuts.  I just asked whether that is the most important of the 3 factors.

By the way, how do you assess the precision of your system (if that's important).  And does the resolution support the accuracy of the SHT31?

[CW2274]

I and a RAWS down the street are both at 1% humidity, the ASOS at 2%. Lets see who stays outta CQ jail and who doesn't.

[WxLover16]

I and a RAWS down the street are both at 1% humidity, the ASOS at 2%. Lets see who stays outta CQ jail and who doesn't.

It's crazy how often you stay AOB 1% humidity. I'm sure hand lotion is owned by everyone over there.

[CW2274]

I and a RAWS down the street are both at 1% humidity, the ASOS at 2%. Lets see who stays outta CQ jail and who doesn't.

It's crazy how often you stay AOB 1% humidity. I'm sure hand lotion is owned by everyone over there.

God bless my whole home humidifier. Outside dew point currently -23F, inside, 52F.

[CW2274]

Just put my spare 31 into the ISS to see if it's as willing to hit and stay at 1% as the old one so often did, and get flagged for it. IIRC this new one averaged about 1/2% wetter than the old one when doing side by's, so maybe it'll not hit 1% so easily, and actually hit 100% too, as the old one would almost never do that either.
Time will tell....

[WxLover16]

Just put my spare 31 into the ISS to see if it's as willing to hit and stay at 1% as the old one so often did, and get flagged for it. IIRC this new one averaged about 1/2% wetter than the old one when doing side by's, so maybe it'll not hit 1% so easily, and actually hit 100% too, as the old one would almost never do that either.
Time will tell....

It kinda sucks. I have tested (unscrewed, screwed, unscrewed, etc...) my ISS so much that the screws and plastic are warped, so everything wants to come apart (or get stuck) when I try to play with the ISS.  Spring cleaning is coming up, too; great!

[dalecoy]

I have tested (unscrewed, screwed, unscrewed, etc...) my ISS so much that the screws and plastic are warped, so everything wants to come apart (or get stuck) when I try to play with the ISS. 

So, if it ain't broke - screw it?

(Sorry - I just couldn't resist)   

[ValentineWeather]

I and a RAWS down the street are both at 1% humidity, the ASOS at 2%. Lets see who stays outta CQ jail and who doesn't.

It's crazy how often you stay AOB 1% humidity. I'm sure hand lotion is owned by everyone over there.

God bless my whole home humidifier. Outside dew point currently -23F, inside, 52F.

I finally put mine away, maybe early the way its going. Got you beat on low dewpoint....-35° This was Jan 1

[CW2274]

Just put my spare 31 into the ISS to see if it's as willing to hit and stay at 1% as the old one so often did, and get flagged for it. IIRC this new one averaged about 1/2% wetter than the old one when doing side by's, so maybe it'll not hit 1% so easily, and actually hit 100% too, as the old one would almost never do that either.
Time will tell....

It kinda sucks. I have tested (unscrewed, screwed, unscrewed, etc...) my ISS so much that the screws and plastic are warped, so everything wants to come apart (or get stuck) when I try to play with the ISS.  Spring cleaning is coming up, too; great!

Jeez, maybe ya outta lighten up on the torque, these's things are very robust.

Only reason I didn't make the swap earlier (had to talk myself into it), gets really tiring getting stuck with cactus needles that make hypodermics look like dull pencils. I usually only go out to it twice a year.

[CW2274]

I and a RAWS down the street are both at 1% humidity, the ASOS at 2%. Lets see who stays outta CQ jail and who doesn't.

It's crazy how often you stay AOB 1% humidity. I'm sure hand lotion is owned by everyone over there.

God bless my whole home humidifier. Outside dew point currently -23F, inside, 52F.

Got you beat on low dewpoint....-35° This was Jan 1

Exactly why I made the swap. Even though the RAWS and myself had the exact temp/dew for 1% humidity (for instance, 90 and -23F), mine stays there, the others do not, hence the flagging. Hitting 1% is not the "problem", it's that it stays there for hours, like a giant hole to climb out of.

[WxLover16]

Just put my spare 31 into the ISS to see if it's as willing to hit and stay at 1% as the old one so often did, and get flagged for it. IIRC this new one averaged about 1/2% wetter than the old one when doing side by's, so maybe it'll not hit 1% so easily, and actually hit 100% too, as the old one would almost never do that either.
Time will tell....

It kinda sucks. I have tested (unscrewed, screwed, unscrewed, etc...) my ISS so much that the screws and plastic are warped, so everything wants to come apart (or get stuck) when I try to play with the ISS.  Spring cleaning is coming up, too; great!

Jeez, maybe ya outta lighten up on the torque, these's things are very robust.

Perhaps my "problem" arose because each time I took it apart and put it back together, I screwed the screws in too tight. Now whenever I try to unscrew just the bottom 3, the top ones that lead to the solar panel bracket come apart with it, which is quite the "adventure" to keep everything where it should be. I think I played with my toy to death. Not sure whether to  or 

[CW2274]

Just put my spare 31 into the ISS to see if it's as willing to hit and stay at 1% as the old one so often did, and get flagged for it. IIRC this new one averaged about 1/2% wetter than the old one when doing side by's, so maybe it'll not hit 1% so easily, and actually hit 100% too, as the old one would almost never do that either.
Time will tell....

It kinda sucks. I have tested (unscrewed, screwed, unscrewed, etc...) my ISS so much that the screws and plastic are warped, so everything wants to come apart (or get stuck) when I try to play with the ISS.  Spring cleaning is coming up, too; great!

Jeez, maybe ya outta lighten up on the torque, these's things are very robust.

Perhaps my "problem" arose because each time I took it apart and put it back together, I screwed the screws in too tight. Now whenever I try to unscrew just the bottom 3, the top ones that lead to the solar panel bracket come apart with it

Okay, I know exactly what you've done. The long screws at the bottom screw into the long hex nuts atop which attaches the bottom portion of the ISS to the top two covering plates over the fan. The hex nuts (metal) are seated into the top hex receptacle, which is plastic. You've stripped the plastic so that the screws and the hex nuts are merely turning as one. You're going to need to disassemble the ISS by getting a wrench into the plates and wrench the screws and nuts apart, then determine whether the plastic portion that houses the nuts can be salvage. If not, this is a very cheap fix, as I just bought both top plates as they were shot after ten years in this sun.

Now, ask me how I know this....

From one who over torque's to another.

[DaleReid]

While not related to screw torque at all,I'm thinking you guys will have had considerable experience with that chip, or have more   info than I do by a long shot.

I'm interested in using that chip for outside temp and humidity, but wonder how long of a cable run one can have?

The rig I'm building will be inside, near my favorite position to watch weather things, which means a six foot cable is just the start.  To get into the best outside spot and back to the electronics, I'd need at least 35' maybe 50' run.

I know the BME280 chip isn't supposed to have a run of more than a few feet.  Plus it has a barometer which isn't needed.

Thoughts?  Experience? Just hoping someone will have real world experience.
Dale