Who here makes RTD Sensors?

[NineInchNails]

I saw one topic here where someone showed making PT100 RTD Sensors quite a while ago. Would anyone who has experience at this have a link to sources for the wire & the sensors? I've been searching around, checked Omega Engineering, Amazon, eBay and I'm not sure which to go with.

One of Auber RTD Sensors got wet, created suction in my thermowell and I evidently pulled too hard or something and it all came apart. I'm trying to put it back together, but ordered a new one from Auber. I would like to have a few more and would prefer to make them myself to save money. The Auber one appears to be a thin film sensor. It's an extremely small, flat, square element.

[jimmayhugh]

Adafruit normally sells both PT100 and PT1000 3-wire probes, but it looks like they are currently out of stock.

Are you looking for PT100 or PT1000 probes? Are they inserted into a thermowell, or and integral part of a TC or NTP probe? Or are you looking for just the sensor and you'll add the wiring?

[Mr Sippy]

I use digikey for all my stuff.
https://www.digikey.com/product-detail/ ... ND/6560922.

I have 4 of these on my still. 3 years, no problems.

[NineInchNails]

Adafruit normally sells both PT100 and PT1000 3-wire probes, but it looks like they are currently out of stock.

Are you looking for PT100 or PT1000 probes? Are they inserted into a thermowell, or and integral part of a TC or NTP probe? Or are you looking for just the sensor and you'll add the wiring?

I've been using PT100 sensors from Auber.

I was considering wiring them myself and slide them into a piece of copper tubing with the end soldered closed. I insert them into thermowells.

I'm considering soldering them to wire, insulate leads with kapton tape and likely use JB weld to seal the wire to the copper tube. If there's a significant cost savings, I'd be happy to make them myself.

[NineInchNails]

I use digikey for all my stuff.
https://www.digikey.com/product-detail/ ... ND/6560922.

I have 4 of these on my still. 3 years, no problems.

Not a bad price. Just a couple bucks less than Auber.

[Mr Sippy]

I put them in copper tubing also. They're a bit loose so I squirt a bit of thermal paste in also. Then sleeve the tubing and cable with heatshrink to hold in place.

[NineInchNails]

I put them in copper tubing also. They're a bit loose so I squirt a bit of thermal paste in also. Then sleeve the tubing and cable with heatshrink to hold in place.

Where did you buy the sensors and the wire? I've been shopping around, but I hoped you guys who have been doing this would know best.

I managed to fix the sensor I accidentally pulled apart. I insulated the connections using kapton tape, slid it in a little ways then used JB Weld to glue & seal the wires as I pushed it the rest of the way in.

[Mr Sippy]

NIN-- regarding terms: I consider the rtd as the sensor. It needs a device to interpret and display the signal. I use a microprocessor programmed for still operation. If I need the wires longer I use regular old phone wire. I believe there are some arduino tutorials around for rtd readout. Not sure if there is any kind of plug n play thing.

[NineInchNails]

This page shows what an RTD sensor is comprised of. When my Auber sensor pulled apart there is only 3 wires soldered to a tiny little element, small as a crumb. The leads were insulated with kapton tape, installed inside of a stainless tube and some glue to seal and adhere it.

I saw a thread here from a long time ago talking about making these RTD sensors by buying the wire, the RTD element itself, soldering the connections, insulating the leads and gluing them into copper tube ... only he didn't list any links. This is what I'm talking about. I'm interested in making my own RTD sensors IF there is a significant cost savings.

I'd like to make longer ones for instance where Auber sells 6' sensors.

[Mr Sippy]

Gotcha. Believe that piece is called resistance thermometer element. Quick search didn't yield much. Absent any other advice you might try calling digikey. Theyr'e very good on customer service. Good luck.

[jimmayhugh]

A quick check at Digikey shows them at $3.43 unit quantity, plus shipping (usually about $10).

Once you include wire, tape, etc, plus your time to make them, I question if it's cheaper...

[NineInchNails]

A quick check at Digikey shows them at $3.43 unit quantity, plus shipping (usually about $10).

Once you include wire, tape, etc, plus your time to make them, I question if it's cheaper...

The wire appears to be approx 53 cents per foot at this place which is the first place I found it. Would be better if I could find a one stop shop for the additional cost for shipping. I'll keep looking. I'd like to find the same kind of wire Auber uses. It has a white and two red insulated wires combined.

[NineInchNails]

A quick check at Digikey shows them at $3.43 unit quantity, plus shipping (usually about $10).

Once you include wire, tape, etc, plus your time to make them, I question if it's cheaper...

Thanks for that link! That is very helpful.

If you buy 5 then they cost $3.19 each. Shipping is $4.99 so that's not bad. So with shipping they are $4.18 each.

I contacted that company and they said they do not sell AU Plated Nickel Wire which they said is appropriate for those sensors. Not sure that kind of wire is required.

[NineInchNails]

I just called this company using their store locator and they quoted me $0.48 per foot for 22 gauge red red white wire shown in this chart. I'm NOT getting 22 gauge, I'm getting 24 gauge RT24-3-527 so it should be pennies less per foot. I just thought I'd share the source if anyone was interested. He said they charge actual UPS shipping cost.

I haven't done a total cost per unit analysis, but it should be only a few bucks less than buying them. At least you can make them any length you want.

RT24-3-527 Wire
RTD Sensor Elements $4.18 each including shipping
Copper Tube 2' 4mm x 0.5mm $7.49 free shipping
RTD Sensor Female Connector $2.99 + shipping
A little bit of JB Weld or adhesive of choice