Author Topic: Davisí Stainless Temperature probe response time  (Read 612 times)

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Offline jgentry

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Davisí Stainless Temperature probe response time
« on: March 10, 2018, 06:33:54 PM »
Is it me or does anyone else thinks that Davis stainless temp probe responds faster to temperature changes than the SHT 31 in the VP 2? If it does responds quicker to temperature changes, why does Davis use Sensirion sensor chip instead of using a temp/hum stainless steel probe for their stations?
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Offline SLOweather

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Re: Davisí Stainless Temperature probe response time
« Reply #1 on: March 10, 2018, 07:41:59 PM »
Do you have a link or model number for a stainless steel temp/hum probe? Those of us near the ocean would be interested.

Is it me or does anyone else thinks that Davis stainless temp probe responds faster to temperature changes than the SHT 31 in the VP 2? If it does responds quicker to temperature changes, why does Davis use Sensirion sensor chip instead of using a temp/hum stainless steel probe for their stations?

Offline Felix1

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Re: Davisí Stainless Temperature probe response time
« Reply #2 on: March 10, 2018, 09:04:34 PM »
Do you have a link or model number for a stainless steel temp/hum probe? Those of us near the ocean would be interested.


I'm assuming the OP is talking about Davis item #6470 which is temp only...I'm not aware of any combo temp/humidity sensor in stainless. It's presently $34 at Scaled Instruments although Ryan's new postage and shipping charges frequently make an item's total cost more expensive than from other Davis discounters. i don't play the price-match game, whichever reputable retailer has an item advertised the cheapest (overall) gets my order. 


I'll agree, the 6470 response time is very quick.

Offline pfletch101

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Re: Davisí Stainless Temperature probe response time
« Reply #3 on: March 10, 2018, 09:07:18 PM »
As I think SLOweather is implying, it is fairly easy to make a pure temperature sensor which is hardy, has minimal drift, and responds quickly to changes; to do the same for humidity and/or the combination is much more challenging.
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Offline jgentry

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Re: Davisí Stainless Temperature probe response time
« Reply #4 on: March 10, 2018, 09:23:51 PM »
Do you have a link or model number for a stainless steel temp/hum probe? Those of us near the ocean would be interested.

Davis doesnít make one sadly to say. I was making reference to Davis temp probe #6475
https://www.davisnet.com/product/stainless-steel-temperature-probe-with-rj-connector/

I was just wondering why they wouldnít use a stainless steel probe as their temp/hum sensor. My apologies for the confusion.

Is it me or does anyone else thinks that Davis stainless temp probe responds faster to temperature changes than the SHT 31 in the VP 2? If it does responds quicker to temperature changes, why does Davis use Sensirion sensor chip instead of using a temp/hum stainless steel probe for their stations?
Davis Vantage Pro2. SHT-75. WU: KXALJEMI2 & KALTHORS2. CWOP/APRS: C6353 & E6358

  

Online johnd

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Re: Davisí Stainless Temperature probe response time
« Reply #5 on: March 11, 2018, 06:23:40 AM »
Is it me or does anyone else thinks that Davis stainless temp probe responds faster to temperature changes than the SHT 31 in the VP 2? If it does responds quicker to temperature changes, why does Davis use Sensirion sensor chip instead of using a temp/hum stainless steel probe for their stations?

I doubt that the SS probe does intrinsically respond any faster to changes in air temperature. Your post is not really comparing like with like - the SHT T/H sensor is buried right inside the shield whereas the SS sensor is presumably just out in the open air.

If you had the two sensors side by side on the bench then my guess is that response times would be pretty similar. Your point is probably more about the effect of a (non-FARS) shield on response times than about any difference between the sensors.
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Offline jgentry

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Re: Davisí Stainless Temperature probe response time
« Reply #6 on: March 11, 2018, 02:09:00 PM »
Is it me or does anyone else thinks that Davis stainless temp probe responds faster to temperature changes than the SHT 31 in the VP 2? If it does responds quicker to temperature changes, why does Davis use Sensirion sensor chip instead of using a temp/hum stainless steel probe for their stations?

I doubt that the SS probe does intrinsically respond any faster to changes in air temperature. Your post is not really comparing like with like - the SHT T/H sensor is buried right inside the shield whereas the SS sensor is presumably just out in the open air.

The SS probe is housed in a passive radiation shield. I also have a 24hr FARS with a SHT-31. In the 24hr FARS, I see .1į-.2į changes quickly but never a whole degree change in a 10 second timespan. Also, there are more .2į changes than Iíve noticed with the SHT-31. Thatís why Iím thinking that the SS probe has a faster response time. I also was thinking that was due to the sensorís filter.

My thinking is that a SS probe is a better design than a sensor chip housed in a fairly big filter cap. Then again, I could be wrong.  Thoughts?

If you had the two sensors side by side on the bench then my guess is that response times would be pretty similar. Your point is probably more about the effect of a (non-FARS) shield on response times than about any difference between the sensors.
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Offline EA1EF

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Re: Davisí Stainless Temperature probe response time
« Reply #7 on: March 13, 2018, 05:57:45 PM »
Remember that the temp probe is a simply NTC resistor 10k 0.5% accuracy that cost raw 2 dollars or euro. In Europe Davis 6475 inox probe sold in 75 euro... Too expensive.

It can plug directly in central pins of th conector ISS T/H port.

We use for swimming pool solar warm monitoring, also in snow gradients monitoring.

When use in soil station the resolution are bad, 0.5 degree...
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« Last Edit: March 13, 2018, 05:59:25 PM by EA1EF »