I have a temperature probe off a old multimeter (thats long gone) have kind is it. It is a two wire kind that has banana incerts. Are those generaly just a resistants type? Reduced voltage the hotter it get or the colder it gets. So can i just put it inline with a pinout and be fine. And if so what Scketch example should i use to start off with ? Thoughts and suggestions :) ?
All the multimeter probes I've seen are thermocouples - is the end just two metal wires fused into a little blob? That's a thermocouple.
Most will be a 'K type' thermocouple, Two metals - Nickel Chromium and Nickel Aluminum in one probe, they generate a millivolt signal depending on temperature.
so a standard meter will show millivolts ? correct ?
ow - and if so what example scketch would be a good start ?
woody_unreal: so a standard meter will show millivolts ? correct ?
Standard multimeter chips support directly outputing temperature in C and F direct from a thermocouple, see for instance the datasheet for the FS9922-DMM4 mentions K-type thermocouple in the example circuit for temperature measurement.
Look for the datasheet for - AD594 or AD595 which are K type thermocouple ampilier IC's.
does this help in the type of it ?
start with measuring ohms, that’s a good start…
PT100 = 100 ohms @ 0 degree Celsius
PTC10K = 10K @ 25 degree Celsius (ptc is positive temperature coefficient ant ntc negative)
and so on…
thanks. i wil work that way , and go from there :)
If it is a PT100 temperature probe, its resistance at room temperature (25'C) should be around 110 Ohms,
at 50'C its resistance will be around 119 Ohms and at 100'C it will be around 138 Ohms