Electronic – arduino – What happens when reaching the max temperature on a temperature sensor

arduinotemperature

I need to monitor the temperature of a hot plate so it stays at 210C

I am just using a Arduino and lcd to display the temp using a DS18S20 (I have it ready but not actually using it to measure the plate with this) but that's only rated to 100C so I am buying a LM34CZ DKF503N5 / DKF103N5 which goes to 250C.

My question is what will happen if it goes above 250? will it de calibrate it? will it explode? or something else? It is possible that it could go higher than that but for short periods of time until I can get the correct temperature on the plate.

I did read a few datasheets and it does not say anything about exceeding the rated temperatures.. that is why I am asking you experienced guys..

EDIT

Sorry I was on a US site and never realised it was F i switched over to UK and got the correct ones.. completely different models though

Best Answer

Thanks to 0x6d64 for pointing out the C/F discrepancy.

The data sheet says:

Rated for full −50° to +300°F range

In C that is -45°C to 148°C - not enough for your needs.

Your main problem at that kind of temperature is going to be the melting of the solder you're using to attach the LM34CZ.

Personally I'd use a thermocouple. Rated an hundreds of degrees (usually 400+), they allow you to keep all sensitive circuitry away from the hot area.

You'll need a converter chip to allow you to reliably use a thermocouple of course. Most people use the MAX6675, but that is being phased out to be replaced by the MAX31855.

Both are surface mount, so you'll need to etch a PCB to mount it on, or get a breakout board (8 pin SOIC).

Both the chips are pin compatible with each other, and provide an SPI interface the Arduino can talk to easily.

I have had a MAX6675 working on my Arduino, and am waiting for some MAX31855's to arrive so I can check to see if my Thermocouple Library for the Arduino works with them.