Author Topic: Differences between Davis Temp Probes?  (Read 311 times)

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Offline JohnN

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Differences between Davis Temp Probes?
« on: April 29, 2021, 02:30:16 PM »
The temperature probe I had in my pool went bad, so I'm looking to replace it. I see Scaled Instruments has 3 different options with a wide price range, so I'm wondering what the difference is between the 3 and why I'd choose the most expensive probe over the cheapest one. I can see the basic differences that one is sealed in plastic while the others are stainless steel and one is two wires while the others are RJ-45 connectors, but I don't see how those justify the price differences.
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Online johnd

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Re: Differences between Davis Temp Probes?
« Reply #1 on: April 29, 2021, 04:10:25 PM »
The 6470 non-RJ11 one has sturdier cable suitable for burying is one difference.
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Offline JohnN

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Re: Differences between Davis Temp Probes?
« Reply #2 on: April 29, 2021, 06:05:54 PM »
I have a pipe buried that I run the wires in, so I think any wire should be suitable in my case.
www.monmouthcountyweather.comUK Met Office: 45560463
Twitter: @John_N_WxCoCoRaHS: NJ-MN-64
CWOP: E1682Davis Vantage Vue, Pro2Plus w/24 hr FARS, Ambient Weather WS-1000
PWS/WFY: SOUTHARDNJCumulusMX
Wunderground: KNJHOWEL11
                       KNJHOWEL15
LiveATC: KWRI/KNEL/New York Center
             KMJX/KBLM/3N6/N12

Offline azchrisf

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Re: Differences between Davis Temp Probes?
« Reply #3 on: May 01, 2021, 01:24:50 PM »
They are all 10k NTC thermistors.
If you want to save money and have it work like the Davis plug and play,
You can find them in a lot of places.

Here for example:
https://www.ebay.com/itm/383709719796

I’ve used a few of these to replace the Davis ones that have gone bad on my soil stations.
Davis Vantage Pro 2 Plus 6163 w/ 8 Transmitters!
Also doing Soil and Leaf 4x
WU: KAZGLEND106 CWOP: FW1398 (F1398) Purpleair: 98793/LAZGLEND8

Offline JohnN

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Re: Differences between Davis Temp Probes?
« Reply #4 on: May 01, 2021, 04:54:20 PM »
They are all 10k NTC thermistors.
If you want to save money and have it work like the Davis plug and play,
You can find them in a lot of places.

Here for example:
https://www.ebay.com/itm/383709719796

Iíve used a few of these to replace the Davis ones that have gone bad on my soil stations.

Something like that looks perfect. I was thinking of buying a generic one but wasn't sure the exact specs, and didn't know where to find the resistance range for the Davis ones.
www.monmouthcountyweather.comUK Met Office: 45560463
Twitter: @John_N_WxCoCoRaHS: NJ-MN-64
CWOP: E1682Davis Vantage Vue, Pro2Plus w/24 hr FARS, Ambient Weather WS-1000
PWS/WFY: SOUTHARDNJCumulusMX
Wunderground: KNJHOWEL11
                       KNJHOWEL15
LiveATC: KWRI/KNEL/New York Center
             KMJX/KBLM/3N6/N12

Offline doubleohwhatever

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Re: Differences between Davis Temp Probes?
« Reply #5 on: May 01, 2021, 05:05:25 PM »
Keep in mind that NTC thermistors from different manufacturers have different response curves.

10k NTC thermistors are usually centered around 25C. So two sensors with different response curves will have a similar output within a few degrees of center (25C). However, they will diverge the farther you get from center due to the different response curves.

Take a look at the second page in this Davis datasheet to see what I'm talking about:
https://www.davisinstruments.com/product_documents/weather/spec_sheets/6475_6477_SS.pdf

Offline azchrisf

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Re: Differences between Davis Temp Probes?
« Reply #6 on: May 01, 2021, 10:06:04 PM »
That is correct. Most are but some aren't.
Make sure the centerpoint is 25c.
Davis Vantage Pro 2 Plus 6163 w/ 8 Transmitters!
Also doing Soil and Leaf 4x
WU: KAZGLEND106 CWOP: FW1398 (F1398) Purpleair: 98793/LAZGLEND8

Offline azchrisf

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Re: Differences between Davis Temp Probes?
« Reply #7 on: May 03, 2021, 03:52:55 PM »
JohnN,

I'm gonna caution on this, even though these will work in most situations since yours is always submerged in water that's probably a case where the Davis might be sealed a little better for that need vs. the generic ones. Eventually though, water will find a way past the potting material and get into the sensor no matter what brand.

If your OK with replacing these sensors every few months (they are so cheap if you find them in bundles) you'll probably save money in the long run, but at the cost of having to replace more often. I'm not saying that WILL happen but it's a definite possibility if they are 100% submerged beyond the top of the metal case.
Davis Vantage Pro 2 Plus 6163 w/ 8 Transmitters!
Also doing Soil and Leaf 4x
WU: KAZGLEND106 CWOP: FW1398 (F1398) Purpleair: 98793/LAZGLEND8

Offline JohnN

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Re: Differences between Davis Temp Probes?
« Reply #8 on: May 04, 2021, 11:05:16 AM »
I found a 5-pack on Amazon for $10 that I'm going try. Couldn't find the spec sheet so I'm not sure if they'll match the Davis, but for $10 it's worth a shot. This Davis one lasted around 2 years I think, so even that doesn't seem to have the longest life anyway. So even if I have to replace them every few months, I'll probably still come out ahead of replacing the Davis every 2 years.
www.monmouthcountyweather.comUK Met Office: 45560463
Twitter: @John_N_WxCoCoRaHS: NJ-MN-64
CWOP: E1682Davis Vantage Vue, Pro2Plus w/24 hr FARS, Ambient Weather WS-1000
PWS/WFY: SOUTHARDNJCumulusMX
Wunderground: KNJHOWEL11
                       KNJHOWEL15
LiveATC: KWRI/KNEL/New York Center
             KMJX/KBLM/3N6/N12

 

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