Need remote temperature measurement with analog meter display

[gandytable]

Need a method to measure temperature remotely and display on an analog meter. We presently use remote reading vapor actuated dial thermometers, which use a capillary tube. These work well, but the machines they are mounted on are broken into sections for shipping. Presently the thermometers are mounted on a section, so that it is not necessary to disconnect the capillary. We want to panel mount the temperature gauges in a central location, and 20 foot long capillaries that would need reconnecting are problematic. Would like to use RTDs, thermocouples, or whatever works, but our industry wants an analog meter (dial type) display. Automotive type analog gauges are fine, but need a temperature range of about 100F to 210F with 2 degree increments and 3 degree accuracy. How can I do this? What manufactures have this type of temperature gauge?

 

[btrueblood]

You may be stuck doing a "do-it-yourself" with an amplifier and analog panel meter. Suggest posting in the electrical/electronic engineers, circuit engineering forum.

 

[Chuckles159]

The National LM34 outputs 10mV per degree F. 210° = 2.1V output. The LM35 gives 10mV per degree C. Both will work to 210 °F. I have used these to monitor block temperaure at various points in my engine.

Just feed the output to an appropriately scales analog meter movement. Or a Digital meter if you like.

 

[Warpspeed]

Another way would be a standard commercial RTD or thermocouple temperature module with 0-10v output, and just hook up an analog meter movement with an appropriate temperature scale.

It is usually fairly easy to find a meter scale in volts, microamps, (or whatever) that has the correct scale divisions and numbers to correspond to temperature.

Alternatively the better meter suppliers will be able to provide a custom scale with the units measured, name of the parameter, coloured sectors, or even company logo for a nominal charge.

 

[WGJ]

You could have a look at the PicoTech website - they specialise in remote monitoring/data acquisition, their Enviromon system is on:

http://www.picotech.com/enviromon.html

You may also find some interesting temperature measurement info at:

http://www.autonerdz.com

And, there is a product from Quasar Electronics:

http://www.quasarelectronics.com/3145.htm

The Quasar stuff starts at about $70 for 4 channels and a temp range from about -30ºC to 125ºC.

However all these need a basic PC to run them and to display the temperatures, usually as a moving graph, like a strip chart recorder, or simply as numbers.

More complex temperature monitoring systems* can give you an analogue meter type output via a PC screen. I imagine that someone that is conversant with Visual Basic could do the same with the stuff mentioned above.

*For these, also look at:
Adept Scientific

http://www.adeptscience.co.uk/tcm/tcm33/measurement.html

Windmill Software

http://www.windmill.co.uk/

Monitor Newsletter (ISSN 1472-0221)

National Instruments:

http://www.ni.com/temperature/

To get over the difficulties with breaking down equipment for shipping, the PC-based option may offer a way out.

 

[WGJ]

Forgot this lot - thet're good and can help on the software side to give you analogue gauges on a PC display.

http://www.datx.com/default.htm