Its to my understanding that the digital does not work with the Vantage Pro , but does work with the Vantage Pro 2
That’s my understanding too, this would only be news if trogdor has an original VP :?
I suspect that there must be some other explanation because this is not the case in my experience and certainly doesn’t tie in with the official dealer guidance from Davis for replacement VP2 T/H sensors.
Just in case my memory was playing tricks, I’ve had a check back this morning with a couple of 2005 vintage VP2 SIM boards, one cabled and one wireless, and in each case they work fine with a .029 ‘analogue’ board, but just give a dashed-out T/H display with a .166 ‘digital’ board (a .166I version in fact, which I think is the same as is currently packaged in the 6930 T/H upgrade kit). This fits in completely with what we’ve been told by Davis about the pre/post-2006 differences.
I’d be interested to know the Mfg Code of your VP2 but what I suspect may have happened is as follows: the post-2006 SIM boards can use either .029 OR .166 T/H sensors. In other words, the .029 part (if only they were still readily available) is univerally usable with all VP2 stations, but the .166 is officially post 2006 only. Although 1st Jan 2006 was the official switchover date when the dual T/H capable SIM boards were introduced, it’s entirely possible that they started to be included in VP2 production runs before the end of 2005. So you might have been lucky enough to get a dual-capable SIM even though the Mfg Code may predate A60101…
(Of course there may be other explanations for your experience, such as your VP2 SIM already having been previously replaced or conceivably and inadvertently you’ve been supplied with one of the last remaining .029 boards or that there’s some trick that I’m unaware of to make the .166 sensors work with the original VP2 SIM boards.)
Overall, I’d still caution anyone with a VP2 whose Mfg Code starts with A4 or A5 and who is still using the original SIM board against thinking that a .166 T/H or 6930 kit will work with their existing VP2 SIM - the chances are that it won’t. But if anyone else has a similar story, ie an original A4 or A5 Mfg Code VP2 SIM board that they’ve found works with a .166 T/H sensor then I’d be more than interested to hear about it. (I suspect in practice that there aren’t too many original SIMs in use any more, with them having been replaced because of supercap problems, but I guess there are still some out there.)
Thanks for the corrected info :oops:
Hi guys, I guess it’s getting to the time when the A5 VP2s fail 
It seems that there are no more .029 boards anywhere (Prodata no longer have them in stock), so I thought I’d take mine to bits and see if I could source the humidity sensor only (someone mentioned it’s a Sensirion sensor). Well, the bad news is that it is not a Sensirion sensor, at least not in my VP2, and I cannot identify it! I’ve included a few pics below of the board and the sensor…if anyone can indeed confirm this is the 029 board, that would be a great help, and if anyone has seen a humidity sensor like the one pictured, please let us all know! For info, there is NO sealing on the sensor, just a push on cap, and it just plugs into the sensor board using a standard SIP socket…
Sensor board
Sensor board again
The sensor itself (at least twice real size!)
The sensor measures approx 6mm x 15mm without the pins - the pins are another 4mm long.
Steve
Hi Steve et All,
You might want to check out this place and see if they might have your sensor.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1966708&k=humidity%20sensor&stock=1
Hope that this might help a bit.
–Stan Y.
Maui, Hawaii
Thanks Stan, there’s nothing there that appears to be an exact match, but if we could find the specification of a working sensor, then I am sure we could source an equivalent…which has to be better than a bill for a new ISS plus a new TH board (about 350GBP by my reckoning :x)
So…any electronics wizards with a working .029 TH board who fancies measuring the sensor…at the moment I am not even sure if it’s capacitive or resitive as mine doesn’t appear to measure either way
Steve
EDIT Looking at the specs, it’s probably capacitive, as the resistive ones only seem to measure 5-95% and the Davis specs are wider than that…
Might be worth a shot to email Davis and see if they will give you the specs.
All they can do is say no.
The newer, currently used sensor is a sensiron.
Hi Steve et All,
Another site to compare http://www.mouser.com/Search/Refine.aspx?Keyword=humidity+sensor&FS=True. Looks about the same as my previous post but this place may have more choices to compare with what you are looking for. I agree with looney2ns and see what Davis reply might be.
–Stan Y.
Maui, Hawaii
Thanks again Stan…if I can get the specs then I am sure I stand a chance of getting something!
Niko, I understand it’s a Sensirion SHT-11 sensor, for another couple of pounds you can get a SHT-15 which has much better specs. Unfortunately, this is a digital serial data device that needs to be interrogated by the ISS, which is why it can’t be used in place of the old analogue board which has 2 separate discrete devices.
Looney2ns, I have tried that…am awaiting a reply…I’ll post the result when Davis get back to me!
Thanks again all,
Steve
I tried Davis, and in looney2ns words…“all they can do is say no…”
I am sorry, but we do not have any design specs to distribute for the Temp/Hum sensor board.
The transmitter module would have to be replaced along with the TH sensor board, since both are needed to accomodate the new digital TH sensor.
I will copy my supervisor on this email, so that your request can be seen by the higher-ups.
Sincerely,
Brian Carpenter
Technical Support Representative
Davis Instruments
(510) 732-7814
Honeywell capacitive sensor
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=480-2904-ND
Spec sheet:
http://www.honeywell-sensor.com.cn/prodinfo/sensor_humidity_moisture/datasheet/HCH-1000.pdf
http://sensing.honeywell.com/index.cfm/ci_id/146573/la_id/1/document/1/re_id/0
George
Interesting to see that that board appears to have pads and connections ready for the new sensor as well (which uses different wires in the cable), so I’m guessing there was a period of crossover in the designs…
My Temp/Hum sensor has recently failed, and the board/mounting arrangement is a bit different to what was posted here, so I thought it might help someone else if this thread was updated.
The first picture shows the back of the board which is marked with 7346.176J as opposed to the 166 versions that were current when this thread was started. The board appears to be very similar, but the epoxy weather-proofing has been further improved.
The second picture shows the board, mounted on an offcut of old circuit board, which is what Davis used as a carrier to hold the sensor in the middle of the Wind Tunnel at the centre of my 24 Hour SPFARS.
The sensor board was manufactured in 2009, although I didn’t buy my VP2+ until early 2011. It lasted just 6 months beyond the 2-year warranty period when the temperature started intermittently ‘dashing out’ on the VP2 console. A few weeks later, the temp. was always dashed out, and now the hum. has dashed out too. Around the same time, the fan stopped working, so I will be ordering some replacement parts for that at the same time.
The “Davis 6930 - PRO2 Temperature Humidity Upgrade Kit” looks like the only way to get a replacement temp/hum sensor, short of buying just the sensor element, and attempting some SMD soldering, repairing epoxy weather-proofing etc. I’m not convinced it’s worth the effort when the 6930 kit costs just over US$100.
It is pretty disappointing that the temp/hum sensor has failed at such a young age. If I add this to the remote Anemometer Transmitter kit that failed, and a remote Temperature Station that failed, my much anticipated Davis Weather Station has been a bit of a let-down, reliability wise. Functionality wise, it is brilliant, but I hope that my next temp/hum sensor might last more than 2.5 years!
one thing to note is that other station types also have similar problems with humidity sensors
My humidity sensor has started to read high
but I have compensated for that in WD with the ability to set a sloped offset…works really well
An update to my post above. After trolling through every part available at Archer Trading Post, I managed to find the following which is just a Temp/Hum Sensor board with cable, and nothing else:
Davis 7346.166 - Pro2 Digital Temperature Humidity Sensor
It’s a bit cheaper than the 6930 upgrade kit mentioned above, which is nice.
I have found several humidity sensor chips for the old Davis Vantage pro boards. These can just plug in to replace the faulty sensor. However, it may require calibration.
If you need one, please let me know, I will sell for a fair price.
Could you post your location, and where you are able to ship?
I’d also be interested.