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WS-1090 Calibration Time

Posted: Fri 16 Sep 2011 3:32 pm
by WoodburyMan
Wondering if any other WS-1090 (or 1080 or any ambient/fine offset user) can gie me some pointers on how long the sensor takes to calibrate.

I have only operated my WS-1090 for just over 30 days now. Still getting used to it. Last night the temp got in the 30F's, and when I set my station up I use regular akaline AA' so I got quite a few "Lost sensor contact" errors in Cumulus, so I decided it was time to switch them out for Lithiums. I disconnected my reciever and made note of the last pressure reading (so I could set it back to that once it came back on). Replaced the batteries with lithiums in the sensor, then hooked my reciever back it. Set the pressure back to what it was for relative. However my Humidity sensor seems to be acting odd. Before it shut off it was around 72%. Indoor works fine, but the outdoor unit is consistantly reading 99%. All other things (wind, temp, etc) are working and changing values fine, however the humidity has remained at 99% when it's really just 70%ish humidity out according to the indoor unit and another small temp sensor I have outside. (Dew point is staying exactly 0.3F bellow the temperature). Now the manual said it takes ~1 hour to calibrate.. but it's not been almost 3 hours and it's stil reading the wrong humidity.

Is this normal? Will it eventually fix itself, or should I reset the sensor and reciever when I get home tongiht?

Re: WS-1090 Calibration Time

Posted: Fri 16 Sep 2011 4:57 pm
by AllyCat
WoodburyMan wrote:I use regular akaline AA' so I got quite a few "Lost sensor contact" errors in Cumulus, so I decided it was time to switch them out for Lithiums.
Hi,

Sorry, I can't help with the (possible) problem with the humidity sensor, but IMHO you have a problem with your wireless link (or a more general fault with the transmitter unit). After only a month, regular alkalines should still be giving ample voltage and (1.5 v. AA) Lithium cells should really only be necessary below about zero F.

New Lithium cells do indeed deliver slightly more voltage than alkalines (perhaps 3.7v compared with 3.4v for two) but this shouldn't be necessary (and just might have "killed" your humidity sensor).

There have been several posts about improving the radio link, but personally I would test the link temporarily with NiMH rechargeables (which have a voltage similar to near-end-of-life Alkalines), changing the orientation of the transmitter and logger and positioning away from potential sources of interference until you get NO lost contacts. Try this both with the USB connected and disconnected because the PC is a possible source of interference.

Cheers, Alan.

Re: WS-1090 Calibration Time

Posted: Sat 17 Sep 2011 3:03 am
by WoodburyMan
Thanks for the info! I've read a few issues people have had with the Fine Offsets and the sensor glitching because of a failed circuit. However usually I don't get any errors, maybe one every few days when the WS-1090 is doing a time sync or something perhaps, and none today since daybreak when it warmed up. I was also using "el cheapo" store brand AA batteries that I would never trust, let alone in cold conditions.

Anyway I played with it once I got home. Unplugged my receiver and removed "backup in case USB/PC power is lost" batteries, and then disassembled my heat shield and took the sensor out. I waved the thing around and put it in front of a fan to "dry out" any moisture that might have been in it that screwed the readings up, plugged it in, got a good 70% humidity reading and I was good... kinda. (I however had to go back and unplug it a short while later since I accidentally reversed the Wind and Rain, whoops! Found that out as soon as i saw 25inches of rain just appeared within a few minutes..). I had to remove batteries from the sensor again when I changed them back to the correct order, and when I plugged it back in again, I got the dreaded 99% humidity again. Tried again with fanning, same thing 99%. Did it a third time, but brought it inside to "warm up" for 5 minutes and it then reported a correct value that was equal to my indoor unit, which I had outside with me to check the readings with. Good enough. Seems on par with stations around here.

So I'm still not sure what happened. Nearest I can figure is when I was touching the unit in the morning, when it was cold (Lower 40F's) my hand might have warmed it and formed dew on the side. Same deal when I was resetting it tonight as it was in the 40F's again. Bringing it inside, in the drier environment and fanning and drying it in there seems to have helped.

In the meantime I have to set Cumulus to ignore any dew point or humidity values of 10% or bellow, as when it lost contact once last night it recorded it somehow and messed data up. Don't get humidity that low usually here.

Re: WS-1090 Calibration Time

Posted: Sat 24 Sep 2011 3:26 am
by WoodburyMan
Well you were correct. Doesn't seem to be batteries causing the issue. In the last 3 days I've had to edit data each day because of odd readings I've been getting.

The station receiver will display "---" for all values that it gets from the outdoor sensor. Most of the time Cumulus will issue a red Warning and log it and leave it at that. However it's sometimes getting odd data. Like the Humidity will read 10%, Temperature -7F, random 25mph wind spike which did not occur, and I apparently accumulated 126in of rain in the matter of 5 minutes.

This happened once or twice before I switched to lithiums as well, but weeks apart. Now I'm getting them almost daily.

My receiver was next to the window which is about 20-25ft from the outdoor sensor unit. I moved the sensor several feet away from the window, closer to the direction of the outdoor sensor. I also have been using a 10ft USB extension. I noticed it becomes loose very easily. I wrapped the connectors together via electrical tape, and also made sure the plug going into the receiver is well attached. We'll see what happens and if I get more errors.

I'm started to get annoyed with the Fine Offset. My Ambient WS-1090 first advertised over 100ft range and when I tried to mount the receiver 30-35ft away (Almost line of sight) I could not get a connection. Now I see the issues on the forum about the humidity/temperature/transmitter unit having a circuit that fails. and now this. Looks like we really get what we pay for with this hardware. Any more large setbacks and I might just go for a David Vantage Pro or something.

Re: WS-1090 Calibration Time

Posted: Sun 03 Mar 2013 3:39 am
by GBock135
Thread bump.

I've been trying to find the answer to the problem I've been having with my WS-1090 for months. Everything indicates correctly except dew point (usually -10 degrees F when it is really 40-50 degrees F) which makes the humidity show dashes (<10%).

Any idea how to fix this? I'm willing to replace a part if I can find it.

Thanks in advance,
Gbock135

Re: WS-1090 Calibration Time

Posted: Sun 03 Mar 2013 9:22 am
by steve
It's the other way around, really. Your lack of humidity reading makes the dew point calculation go wrong. Fine Offset stations can't read below 10%, and show 'dashes' instead. Cumulus converts this to 10%. But if your humidity really isn't that low then you probably have a faulty humidity sensor. The same question was asked here just a day or two ago. Mine does it all the time now.