Topic: new Davis™ VP2 replacement SHT15 temp/rh sensor?

[Old Tele man]

OK, recently there was a LOT of interest expressed in upgrading the current #7436.166 T/RH sensor (SHT11: ±0.4ºC/±3%RH tolerances) in our VP2 stations...well, Davis™ has responded.

Davis now offers a new replacement #7346.174 T/RH sensor (SHT15: ±0.3ºC/±2%RH tolerances) for VP2 stations. The current Davis Minimum Advertised Price (MAP) is $200, but the street price "...will probably be less than Davis's MAP..."

Unfortunately, availability may be slow because they're "Special Order" items with 30-day leadtime and dealers have to make a minimum purchase of 10 at a time.

So, what's YOUR interest?

 

[LABob]

I think the current sensor isn't even that accurate once temperatures get outside of the narrow range where it's rated to those accuracies. The SHT-15 has a much flatter accuracy curve in addition to being more accurate overall. That being said, I'm not interested for $200.

[moehoward4]

The only benefit of this change is to Davis' bottom line, they had to justify a price increase and this is the cheapest way to do it. And on that comment, I'm outta here on this topic...............

[miraculon]

I am not keen on dismantling the DFARS, et al in order to change out something that isn't "broken". Especially in the Winter...

I suppose if it ever goes bad (again) it will be needed.

Greg H.

[ValentineWeather]

This is a response to the Europeans already modifying the sensor SHT-11 with the 15. Likely why Davis offered it in Europe first. Davis seems very concerned about any competition, IE going to the green dot data logger.
As far as the SHT-15 goes I've tried one of the home made units from europe and didn't find the humidity very accurate so went back to sht-11. I wouldn't mind trying another SHT-15, this time directly from Davis but not for retail price of 200. Price difference for the actual sensor I believe was only 10-15$ range. 

[kobuki]

Hm. I find it weird that you found the humidity accuracy of the ST15 is worse than the SHT11 (do I interpret your findings right?). It should be the opposite, really. Let's hope it's not another wave of chinese counterfeit clones.

[Old Tele man]

FWIW:

Davis MAP prices:

#7346.166 @ $175.00 - the current T/RH (SHT11) sensor.
#7346.174 @ $200.00 - the new replacement T/RH (SHT15) sensor.

So, it looks like Davis is asking $25 more for the tighter-toleranced SHT15 over the SHT11. Luckily those are not the street prices, but nobody has listed their 2015 "street" price for this new sensor yet.

[Old Tele man]

Hm. I find it weird that you found the humidity accuracy of the SHT15 is worse than the SHT11 (do I interpret your findings right?). It should be the opposite, really. Let's hope it's not another wave of chinese counterfeit clones.

Well, they DO have a Chinese factory!

Sensirion China Co. Ltd.
phone: +86 755 8252 1501
info@sensirion.com.cn
www.sensirion.com.cn

[kobuki]

Well, they DO have a Chinese factory!

So does FTDI...

You've probably misunderstood the Chinese part -- I have nothing against products made there. The point is on counterfeit, not the manufacturing country. Athough I have heard of more than one brand of counterfeit chips manufactured in China, it doesn't mean anything in this respect.

[ValentineWeather]

Hm. I find it weird that you found the humidity accuracy of the ST15 is worse than the SHT11 (do I interpret your findings right?). It should be the opposite, really. Let's hope it's not another wave of chinese counterfeit clones.

Thats why I would like to see how the Davis unit turns out, hopefully once they ship we will get some feedback, but I'm not going to order at the current price. The chart says the SHT15 should be better, but with the low Az. dewpoints the SHT15 would go way low. Sometimes down in -30 range when actual was closer to -10dp.  So I would calibrate to actual dewpoint and this would effect the dewpoints as they came up causing dewpoint to read high. I could never find that happy middle ground so went back to the SHT11.

[kobuki]

I see, thanks for the insight. Your part might even turn out to be a faulty one...

I'm wondering, what is your reference for calculating DP?

[ValentineWeather]

It could've been a faulty sensor for sure, I used the Local airport and Extech psychrometer for reference and once I went back to the SHT11 problem cleared up.

[mcrossley]

I have been using a couple of home-brew sht-15 (actually sht-75 as they are an easier replacement, no cct board required, just solder to end of the cable) based sensors for a while now. I did have one start to under read humidity, but I followed the sensiron process for cleaning it an allowing reclimatisation, and it worked fine again after that. So, contamination can cause these sensors to under read humidity. They really need a better screen than one Davis supplies, a small Goretex or better e-Vent membrane would be best I think.

[reef]

More options are always a good thing, but Davis are never going to sell these things at $200 (so essentially it will be £150+ here) when people are able to get custom ones for just over a third of the cost.

I've been running a homebrew SHT15 Temp/RH sensor from belfryboy on this very site for three months now and it has been exceptional. The response is quicker due to the smaller filter and PCB, temps are spot on (my Davis sensor was hopeless) and it actually records humidity higher than 96% which my Davis wouldn't.

If Davis really want to do something for the European market then they need to reduce the prices and improve the support. Take for example a replacement 24hrs FARS ISS (Davis 6323); on scaled instruments its $495, here its $1050, meaning its actually cheaper to import and then buy a separate PCB (US wireless versions aren't permitted here).

At the end of the day, people over here are running custom items because Davis either don't offer what they want or if they do its too expensive. I've already switched to a 80mm computer fan to run 24/7 in my FARS as I got sick of the standard Davis fans costing $85 each and failing within a few months. This is what Davis really need to work on.

[CW2274]

Hello folks, new kid on the block here. My 2 cents on this. I've had my vp2 since 2007 iirc and felt the need to replace the sensor this summer due to my anal need for the best I can have and because my data is posted on the local NWS website. The old one was still "satisfactory" but was aware of the drift that time takes on the sensor. I called Davis to see if they offered an SHT15 upgrade which was a big NO. I told them if they were smart they could really cash in on an upgrade since the sensor itself is dirt cheap, so apparently that didn't fall on deaf ears. So I merely ordered one from Senserion in Cali. for $25 and found a guy down the street who does micro electronic soldering. The sensor is really tiny, about one-quarter a pinky nail. 10 minutes later and $20 (he only wanted $15) I was back online. So for $45 I'm really glad Davis didn't have the option at the time. Sensor works beautifully!

[CW2274]

Sir, we are just down the street from each other.

[CW2274]

CW2274, it looks like you're at the west end of Grant Road.

We're just outside the Marana city-limits, and since Marana won't claim us, I decided to claim the unincorporated area of Cortaro, AZ (2 miles SSW) as my weather station location (ha,ha)!

I, too, want the weather data that NWS-Tucson displays from my site to be as accurate as possible.

Little further up in the foothills. Where is you PWS on the NWS site? I can't find it.

[Dr Obbins]

I told them if they were smart they could really cash in on an upgrade since the sensor itself is dirt cheap, so apparently that didn't fall on deaf ears. So I merely ordered one from Senserion in Cali. for $25 and found a guy down the street who does micro electronic soldering. The sensor is really tiny, about one-quarter a pinky nail. 10 minutes later and $20 (he only wanted $15) I was back online. So for $45 I'm really glad Davis didn't have the option at the time. Sensor works beautifully!

Reinforces what I have been saying for some time now. Davis is good equipment, but very overpriced. Charging ~$200 for a $15 item (and then some). Now with that being said, Santa brought me a new VP2+ for Christmas.

[CW2274]

CW2274, it looks like you're at the west end of Grant Road.

We're just outside the Marana city-limits, and since Marana won't claim us, I decided to claim the unincorporated area of Cortaro, AZ (2 miles SSW) as my weather station location (ha,ha)!

I, too, want the weather data that NWS-Tucson displays from my site to be as accurate as possible.

Little further up in the foothills. Where is you PWS on the NWS site? I can't find it.

I'm 2-miles NNE of Cortaro, AZ, here...http://weather.gladstonefamily.net/site/D6988

Oh ok, I see what you're referring to. What I was stating is that my data is displayed on the NWS actual web site under "More Local WX" link. The Western Region of the NWS will show civilian stations on their sites whereas the rest of he country does not. Zero clue why.

[CW2274]

I told them if they were smart they could really cash in on an upgrade since the sensor itself is dirt cheap, so apparently that didn't fall on deaf ears. So I merely ordered one from Senserion in Cali. for $25 and found a guy down the street who does micro electronic soldering. The sensor is really tiny, about one-quarter a pinky nail. 10 minutes later and $20 (he only wanted $15) I was back online. So for $45 I'm really glad Davis didn't have the option at the time. Sensor works beautifully!

Reinforces what I have been saying for some time now. Davis is good equipment, but very overpriced. Charging ~$200 for a $15 item (and then some). Now with that being said, Santa brought me a new VP2+ for Christmas.

You musta peeked! Unless you're Santa.....

[CW2274]

This is what I'm referring to.http://www.wrh.noaa.gov/total_forecast/other_obs.php?wfo=twc&zone=AZZ504

[CW2274]

This is what I'm referring to.http://www.wrh.noaa.gov/total_forecast/other_obs.php?wfo=twc&zone=AZZ504

Never saw that page before.

That kinda looks like a "legacy" website page that pre-dates the fancy map-based GUI interface they're using, which implies that you've been posting for quite awhile.

Whatever you just said is total Greek to me. The page I listed is available on every NWS web site exclusive to that particular area in the country 24/7 and has been as long as I've surfed the NWS. Go to any NWS home page for the particular CWA you're interested in and click on the map to bring up an area forecast and to the right you'll see the "More Local Wx" page. As far as "posting for a while", if you mean my data being displayed by the NWS, it's been about 2 years.

[CW2274]

Take your mouse and click on the map displaying the Tucson CWA somewhere around the city of Tucson. There the small area forecast for the next 7 days for that particular area will be displayed. To the right you'll see the link. Clicking on other areas on the CWA map will bring up other stations if there are any for more personalized Wx in that area.

[ValentineWeather]

My arizona station was listed in the (more local weather) also. Here in Ne. they just use airports and Coops.

[CW2274]

That's because those ARE the only stations displayed by the NWS for the Tucson area. They do not display all of the CWOP stations for the area. If you click down by Douglas for instance, you'll see the only stations in that area be it FAA, RAWS, civilian, whomever, that they choose to display.