I'm looking to monitor three or four temperatures on and around a car engine. I'm looking at what might be the best temperature sensors to use.
Part of the problem is getting the sensor properly thermally connected to the engine and the other parts.
I'm guessing that a thermocouple would work ... I could maybe use crimp connectors like these for mounting:
The temperature range has to go up to about 125C and needs to be "reasonably" accurate. I guess within a few percent, although trends are more important than absolute accuracy.
I'm hesitant to use thermocouples as interfacing them into an Arduino seems like it might be tricky.
The DS18B20 can be had in a robust package that could be crimped into a 6mm connector like that but I think it would be better to make up something in copper or brass that would have better contact.
You can buy DS18B20 encased in Stainless Steel with a 3m cable on EBAY for around $5.
Depending on what and where on the engine you are planning on measuring then these should be fine.
Note the upper range of the DS18B20 is 125c and it loses resolution up from 85c (i believe it drops from .5c to 1c) at that level
Again depending on the application you can simply JB Weld these to the various parts of the engine or use silicon sleeves, compression fittings or hose clamps
MikeVincent:
if that makes any difference to your suggestions.
Not really. The PT100 is available in screw fitting, good for immersion at mains pressure but I have never seen one that would be easily installed in a car, and the DS18B20 is so much easier to use in every other respect.
you can use lm 35 series temperature ic (cost 1$)
for your work.
they are available for range till 150C
just sample 200 times per sec and average them to show the values per sec.
you will surely get the most accurate temperature sensor ever
