temperature measuring element of 18s20


New Member
I hve just received a bunch of 18S20's for temperature measurement.
I assume that the temperature measuring element is theramlly linked to the Ground Pin so if I wish to measure a pipe temperature I need to make sure there is good themal contact between the Ground pin and the pipe.
Is this correct?
This seems not to be mentioned in the datasheet.
I don't know the answer to that question. It may be a bit slower to react but you can definitely get a good reading with contact between the body of the DS18S20 and the pipe.

I can think of earth loops as one problem this might allievate, but it might have issues with UK building control if wiring outside the equipotential zone (for that read house) is not bonded properly.

Be interested to know the answer from some authorative source.

If you accept the limitations of the plastic 'transistor' case, How does one ensure adequate thermal bonding between the case and pipe?

Do you just stick it on with Epoxy? :)
. . . you could use a bit of 'thermal grease' (the kind used between the heatsink and CPU) between the sensor and the pipe . . .