Author Topic: Replace THGR968 sensor for low humidity readings? (Read 17779 times)

Downlinerz2 · « **on:** September 09, 2008, 06:36:35 PM »

Hi again,
I seem to be having the same problem of low humidity (-10%) readings with the THGR968 sensor. I remember from the old forum seeing something about this.
It mentioned a Radio Shack sensor that can be used as replacement. Can anyone tell me the model # or catolog #? Thanks again in advance!!!

mackbig · « **Reply #1 on:** September 09, 2008, 07:53:07 PM »

The model number is 63-1031. I dont think they make/sell them anymore. Radio Shack in Canada became The Source-By Circuit City. They are liquidating a Nextech version right now, but it comes with the base station, and for some reason not available online.

Andrew

Downlinerz2 · « **Reply #2 on:** September 09, 2008, 11:02:58 PM »

Andrew,
Thanks for the information. I was wondering if it would be possible to make a calibration entry in the VWS to correct for these readings? I am making a chart to show how the errors trend over time to see if it is constant or if it varies according to time of day.
thanks again ......

jwyman · « **Reply #3 on:** September 10, 2008, 07:48:00 AM »

Downlinerz2,
I had the same problem you are having with the original THGR968 unit shipped with the WMR968 system. OSI sent my 3 replacements over time and they ALL had the same problem ( lower humidity readings).
They sent me as a complimentary gift a THGR268. It has been rocked solid... Only drawback is that it is not solar-powered, but the batteries seem to last forever in it so no problem there.... I believe the THGR268 has been replaced by a newer unit. Check on the ambientweather site for details....

Jim

mackbig · « **Reply #4 on:** September 10, 2008, 08:08:53 AM »

Jim is correct. From what I have read over the years, most have tossed the 968 sensor. The batteries do last quite a long time in the non-solar remotes. Its probably not worth playing with gains and offsets, as it is probably not off my a consistent amount, unless your analysis shows that your in fact is always of x percent....

The new model for the 268 appears to be THGR122NX. Its actually on sale for less than the old version. Looks pretty similar, it appears that it now takes AAA's instead of AA's

Andrew

Anthony · « **Reply #5 on:** September 10, 2008, 08:09:15 AM »

I am currently using one of the THGR-268 sensors. But I still experience a low humidity reading. So I entered an offset into my weather software (VWS) to compensate.

Downlinerz2 · « **Reply #6 on:** September 10, 2008, 01:21:05 PM »

Anthony, Andrew & Jim,
I really appreciate all the good advice. I had looked on the OS website and saw that the THGR268 was replaced by the THGR122NX. At first I didn't think it was the right one since it looked like the other sensor that came with the 968. I am going to send for the THGR122NX and see how it works. Thanks again for everything. I will report back on how things shake out.
Mark

sam2004gp · « **Reply #7 on:** September 10, 2008, 05:18:57 PM »

Quote from: Anthony on September 10, 2008, 08:09:15 AM

I am currently using one of the THGR-268 sensors. But I still experience a low humidity reading. So I entered an offset into my weather software (VWS) to compensate.

Sort of same here....
After all my testing this weekend I added a +11 offset and at the most it is about +/- 3% of my "Radio Shack Version of the THGR268"(Ch 1). One of my difficulties in getting my problem pinned down, was I also had a bad "Radio Shack Version of the THGR268". Luckily I had 3 of these and i reconfigured their channel IDs, and moved the "bad one" to an area I am not concerned with as far as humidity (My Computer room temp sensor Ch3).

http://www.wxforum.net/index.php?topic=2021.0 <<<<< A long read, and since I turned off the graphic of the extra humidty channels as far as my website is concerned, the thread may be hard to follow. You were warned.

tomwxman · « **Reply #8 on:** September 10, 2008, 06:43:17 PM »

Quote from: jwyman on September 10, 2008, 07:48:00 AM

I had the same problem you are having with the original THGR968 unit shipped with the WMR968 system. OSI sent my 3 replacements over time and they ALL had the same problem ( lower humidity readings).

How long has it been since you tried the replacements? We can hope I suppose that they would make a design change/improvement at some point. The problem I have with using any Ch 1-2-3 sensor is that I want the sensor to appear in the OA sensor part of the WMR968 display--I have two such displays and like to use them as well as the computer program.

I took the THGR sensor apart and as one might expect, there are "no user serviceable parts inside". Looks like if there's any "factory calibration" it involves selection of a soldered-on resistor i.e. there's no on-board pot. FWIW the sensor itself looks like a resistive type. It looks like the first sensor in Photo 2 on this page.

Sure would be nice though if someone could figure-out how to make the standalone sensors w/Ch 1-2-3 to operate on Ch 0 for the correct spot on the 968 display!

W Thomas · « **Reply #9 on:** September 10, 2008, 10:19:41 PM »

It would be nice if there was room for a 10 turn precision pot or something of the like for calibration.
Software calibration works good but something like this would give more headroom in the adjustment area.
I still use the original supplied sensor and I hope it continues to work at least as good as it does now..

Wayne
www.smythweather.net
cw8217

sam2004gp · « **Reply #10 on:** September 11, 2008, 12:32:48 PM »

Quote from: tomwxman on September 10, 2008, 06:43:17 PM

Quote from: jwyman on September 10, 2008, 07:48:00 AM
I had the same problem you are having with the original THGR968 unit shipped with the WMR968 system. OSI sent my 3 replacements over time and they ALL had the same problem ( lower humidity readings).
How long has it been since you tried the replacements? We can hope I suppose that they would make a design change/improvement at some point. The problem I have with using any Ch 1-2-3 sensor is that I want the sensor to appear in the OA sensor part of the WMR968 display--I have two such displays and like to use them as well as the computer program.

I took the THGR sensor apart and as one might expect, there are "no user serviceable parts inside". Looks like if there's any "factory calibration" it involves selection of a soldered-on resistor i.e. there's no on-board pot. FWIW the sensor itself looks like a resistive type. It looks like the first sensor in Photo 2 on this page.

Sure would be nice though if someone could figure-out how to make the standalone sensors w/Ch 1-2-3 to operate on Ch 0 for the correct spot on the 968 display!

Does anyone have any schematics for these sensors. I wonder if Radio Shack did on their re-branded OS WMR-968, I thought I saw some somewhere one time.

W Thomas · « **Reply #11 on:** September 11, 2008, 10:06:35 PM »

I have never saw any form of schematic for any OS device.. Would be nice to see how they are designed!
They must be kinda like a Tripp Lite power supply when they pop you pop em in the can!

I tried my best to get the company to fax ,send or however they would a copy of the print for one of their supplies to
get a part value.. No can do so they said!

Wayne
www.smythweather.net
cw8217

Downlinerz2 · « **Reply #12 on:** September 11, 2008, 10:24:17 PM »

Hi all,
My charting of the readings I am getting from the THGR968 sensor show that the humidity readings are as much as 13% off during the daytime when temps are higher, and that as the temp drops the error drops down to 0% -2%. I did order the new sensor (THGR122NX) that has replaced the THGR268. I am hoping that this
new sensor will correct the problems. If it doesn't, I will have to try a mean correctioon that will not destroy the nightime accuracy, but still bring the daytime readings so that they will more reflect the true humidity. It is a sad thing

that a $200 (MSRP $299), and called "state of the art"

on the OS website has something so fundamentally wrong. I will report how this all comes out on this thread as events transpire. Thank you everyone for the good ideas and the excellent information.
Mark

sam2004gp · « **Reply #13 on:** September 12, 2008, 10:02:48 AM »

Quote from: Downlinerz2 on September 11, 2008, 10:24:17 PM

Hi all,
My charting of the readings I am getting from the THGR968 sensor show that the humidity readings are as much as 13% off during the daytime when temps are higher, and that as the temp drops the error drops down to 0% -2%. I did order the new sensor (THGR122NX) that has replaced the THGR268. I am hoping that this
new sensor will correct the problems.....

^^^^
This was what I also observed on error readings, I left mine at +11

, but was hoping someday someway I could "readjust" the nighttime readings. But by that happens I might just get a different weather station. (nothing in the works at the moment though.

)

In case you did not see my experiments from before....
http://www.wxforum.net/index.php?topic=2021.0

Downlinerz2 · « **Reply #14 on:** September 12, 2008, 03:02:50 PM »

Hi,

I received the new sensor (THGR 122NX) from OS this morning. It is giving me readings that are much more sensible that what I was getting before. However, both this new sensor and the 968 sensor are reading 87% $\:D/$ . Not too sure what to make of this. I am encouraed because the Lacrosse station is also reading the same humidity, and other stations are very close as well. So, as of now I think things will work out with this new sensor

. Thank you all for your help. I will report on this thread if the new sensor lets me down in the next couple days.
Mark

sam2004gp · « **Reply #15 on:** September 12, 2008, 03:21:22 PM »

Also let us know if it stays good. Does it allow you to set your transmitting channel as CH 0?

Downlinerz2 · « **Reply #16 on:** September 12, 2008, 03:25:51 PM »

The sensor does not have a channel 0. I was hoping it would. But only 1-3. Had me a bit confused for a few minutes actually

. I will report how it works over time. Thanks again, Mark

mackbig · « **Reply #17 on:** September 12, 2008, 05:36:59 PM »

That is one of the drawbacks from going from the stock thgr968 to the 268 or THGR122NX, is that you lose your channel 0. So for those of you that actually look at the console.. the outdoor is gone. On VWS its a quick swap of 1 and zero. So for me I had 3 extra sensors plus the 968 for outside, so I had to give up one of my locations, when I made the swap.

Andrew

sam2004gp · « **Reply #18 on:** September 12, 2008, 05:59:26 PM »

Yes that was what I was trying to avoid by putting in the a "somewhat wrong calibration" into VWS for humidity. Most of the time when I look at the console I want the outside and inside temp, windchill in winter, rain rate, and wind speed. When I look at my VWS enabled website usually from work, then I want all the numbers. Since I have no windows in my location of the building.

If there was only a hack to cause the transmitters to do channel 0.

Downlinerz2 · « **Reply #19 on:** September 12, 2008, 07:28:07 PM »

Hi,
This is probably a very

??:dumb question but most of this is really new so here I go. What do you mean when you say you cannot see the outdoor temp on the console if you go to a sensor without CH0? Can't I just set the sensor to CH 1 and punch up CH 1 on the console?

Thanks to all for putting up with my dumb questions. This stuff is wearing me out today. I have spent most of the day trying to switch the VWS from my Lacrosse station to the OS. It just won't do it. But, thats for another board. Mark

W Thomas · « **Reply #20 on:** September 12, 2008, 08:00:21 PM »

Quote from: Downlinerz2 on September 12, 2008, 03:02:50 PM

Hi,
I received the new sensor (THGR 122NX) from OS this morning. It is giving me readings that are much more sensible that what I was getting before. However, both this new sensor and the 968 sensor are reading 87% $\:D/$ . Not too sure what to make of this. I am encouraed because the Lacrosse station is also reading the same humidity, and other stations are very close as well. So, as of now I think things will work out with this new sensor . Thank you all for your help. I will report on this thread if the new sensor lets me down in the next couple days.
Mark

Great news Mark!!!
Maybe they will work like they are supposed to!!

Wayne
www.smythweather.net
cw82217

mackbig · « **Reply #21 on:** September 12, 2008, 09:21:39 PM »

You are correct, you can change the channel display on the console to 1 and that will be displaying your outdoor temp. But the actual "outdoor" channel will be blank. Just make sure when you decommission the 268 you uncheck it on VWS when you click the swap channels button. VWS does not start if it cant find a channel its looking for.

Andrew

Quote from: Downlinerz2 on September 12, 2008, 07:28:07 PM

Hi,
This is probably a very ??:dumb question but most of this is really new so here I go. What do you mean when you say you cannot see the outdoor temp on the console if you go to a sensor without CH0? Can't I just set the sensor to CH 1 and punch up CH 1 on the console? Thanks to all for putting up with my dumb questions. This stuff is wearing me out today. I have spent most of the day trying to switch the VWS from my Lacrosse station to the OS. It just won't do it. But, thats for another board. Mark

Anthony · « **Reply #22 on:** September 13, 2008, 08:16:18 AM »

I've never had the temp side of the stock temp/humid sensor to die. Just the humidity side. So as long as the temp side is working VWS atleast will find it.

Downlinerz2 · « **Reply #23 on:** September 16, 2008, 11:33:02 PM »

](*,)Hi,
Sadly, the good news concerning the readings on this new sensor have not continued, at least for today. All day today, the readings from the new sensor have been haywire. And it is not just the humidity. I have been resetting, moving the sensor from place to place, and nothing has helped. Right now all the other temperature sensors, including my Lacrosse 2317, are reading 53 degrees F and 78%. The OS is reading 61 degrees and 57%. I am going to continue to try and fix this problem. Tomorrow I am putting the tripod on the roof for the wind and rain sensor. I am really glad I can put the temp/hum sensor on the ground. If I cannot come up with a fix for this problem I will probably have to use the Lacrosse station for the temp/hum readings. Is it possible to use both at the same time on the VWS? They both use the same version.
I feel like sending a note to OSI. It is incredible that my $80 Lacrosse has more accurate readings than this $200 station

. I seems that OSI needs to make some significant changes in the Quality Assurrance department. It shouldn't be too hard to calibrate a product to function like it should.

I will update as events warrant, Mark (sorry for the slight rant)

Anthony · « **Reply #24 on:** September 17, 2008, 08:16:05 AM »

Can you use both stations together in VWS? No

News:

Author Topic: Replace THGR968 sensor for low humidity readings? (Read 17779 times)

jwyman