Temp sensors, LM34?

[JTE]

Hi all

I'm looking for a low cost way to measure tempature.

0 - 200F, the system could go over that, max at 300F but we don't need to measure over 200.

I am looking at the LM34, but wish I could find it in a nice package.

More or less a low cost way to get a tempature reading into an Analog card on the DLO6, 0-10 Volt.

Anyone doing anything like this?

 

[JTE]

I'm also looking for a flow meter with an analog output, 4-20 or 0-10 is cool. Trying for $200 or less???? I'm using water and glycol mixture.

 

[panic mode]

what kind of package would be preferred?

you could have LM35 in TO-220... this one has analog out in Celsius but you will have to do scaling in PLC anyway.

 

[JTE]

I was looking for a "package" that was something like a small metal tube with wires exiting it. So that I could stap it onto a water pipe and measure the temp.

I see so many of these "nice packages" in the indusrty but just not sure where to get one or how they are connected to a PLC.

 

[panic mode]

then TO-46 version should do the trick - it's round metal can package with wires coming out of it:
http://instruct1.cit.cornell.edu/Courses/ee476/labs/s2004/LM34.PDF

 

[JNTurcotte]

Were you able to find what you were looking for ?

You are looking for a complete probe kit, stainless tube + wires.
I am looking for the exact same thing. I would prefer to buy it completely done instead of building it myself. That's how it's done in the industry, just that it's done with thermocouples instead of lm34.

But cheap thermometer and thermostat comes with probes in plastic or things like that. Where do they get them from, pretty sure someone produce them.

 

[JTE]

Hi JNTurcotte,
I did not find one yet. Yes you and I are looking for the same thing.

Jim

 

[bce123]

have you tried omega.com

 

[OkiePC]

I recently had to do some PLC-5 change to add some new evaporators. The OEM of the evaporators sent LM34 based sensors, but the distance for the low voltage signal was a concern. And, my packed system had no analog voltage inputs available but several spare mA channels which matched all the existing transmitters.

I ended up ordering RTD probes instead, and never got to use the sensors. I don't know what become of them, but I will dig around later and see if the guys stashed them somewhere, and try to find a part number or something.

Omega has a nice site, good prices:
http://www.omega.com/guides/thermocouples.html

 

[TConnolly]

Try IFM Efector or Kobold for temperature and flow sensors with 10V outputs.

 

[bce123]

I use IMF proxes best ive found

 

[JNTurcotte]

Thank you guys, but not what I am looking for. Either too expensive or would need thermocouples analog converter cards.

I was looking for a cheap solution, something like this
http://www.homebrewtalk.com/f51/diy-submersible-temperature-probe-26400/

http://www.instructables.com/id/Waterproof-a-LM35-Temperature-Sensor/

Might actually have to do it like that, but when you have many, it takes time.