I'm looking for a cheap simple temp sensor chip that measures temp by a known voltage difference from a standard... between 80F to 150F if possible,dry environment.. the kind you hook to a meter and check the voltage difference without any other stuff.. and a source mail order and price??
thanks

 

You can use a digital thermometer like the DS1820 which can measure temperatures between -67F and 257F.

 

Look at things like the LM335 - that works like a temperature controlled voltage reference or zener. Feed 1mA bias current and read the voltage across it.

The voltage drop is 10mV per degree kelvin, so freezing (273K = 0C) is 2.73V, boiling(373K = 100C) is 3.73V.

Also look at the LM34 & LM35, they are three terminal with separate power & output, calibrated 10mV per degree F or per degree C.

 

A thermistor might be the absolutely simplest solution - http://en.wikipedia.org/wiki/Thermistor

You will have to look up the resistance reading on a chart to determine the correct temperature because they are not linear in response.

 

how much for the simple
http://en.wikipedia.org/wiki/File:NTC_bead.jpg
is this at radio shack?
i want to connect to a cheap multi meter and the wires will come out of the wall, about a 16 inch wire run..

 

I believe that a thermocouple sensor measures the temperature based on the voltage difference on the two other ternimals. You could use a comparator or instrumentation amp to equate this difference.