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Author Topic: Will the LM35 go up to 200 deg C?  (Read 1109 times)
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Hey,

This sensor seems popular with the arduino crowd, however I see that it is only rated to 155 deg C.  I need a sensor capable of reading around the range of 200 deg C with the reliability of +- a few degrees.  Do you think I can push the LM35 this high or it won't work?  Any suggestions on other sensors?

Thanks,
Ownage
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I don't think you can/should push it.

At higher temperatures an RTD is often used. Omega claims their RTD's are accurate to within ~2C at 200C:

http://www.omega.com/rtd.html

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Thanks.  They make you buy in packs of 100 though smiley-sad.  I didn't see any other cost effective RTDs.  Is there a cheaper way I can read this temp?
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Possibly automotive coolant temp sensors?  I live by a junkyard.
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How about one of these?

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=615-1045-ND

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A K or J type thermocouple will read these temperatures.
To interface these you will need a thermocouple interface
IC which is typically an SMD part.

I am working with the MAX31855 and K-type thermocouples.
I should have a sketch and schematic later this week.
I am using my PICOBEE board http://wiblocks.luciani.org/PICO/PICOBEE-index.html
to periodically measure temperature and transmit the timestamped data
to a PC.  The MAX31855 has a 14bit ADC and has a resolution
of 0.25degC. Not sure of the accuracy yet.

(* jcl *)
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Thermistors won't last 200 DegC and their housings aren't rated for that temperature. I would use thermocouple too. If you don't need sub DegC accuracy, you can find cheaper infrared remote temperature sensors too.
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I just added a thermocouple + XBee application hint to my site -- http://wiblocks.luciani.org/docs/app-notes/picobee-tc.html.

I interface a K-type thermocouple using the MAX31885KASA. I use the RTC on the PICOBEE
to periodically interrupt the uC. After an interrupt the temperature is read. The timestamped
data is transmitted using the XBEE.

(* jcl *)
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