Vacuum sensor for automotive assisted brakes

Gordon,
As far as I can determine from the data sheets, the compensation relates to automatic level output temperature tolerance between 0 and 50 degrees C. The uncompensated units have no level temperature compensation and you need to use constant current excitation in an endeavour to provide some degree of compensation.

If you can keep the sensor at a constant temperature (car interior ?) then an uncompensated unit may be OK, but if you are that interested in getting accurate vacuum readings wouldn't the extra cost of the fully compensated unit be worth going for.

Compensation has nothing to do with 2nd port connection. Gauge sensors (1 port) measure pressure relative to atmospheric pressure and differential sensors (2 port) measure pressure relative as the difference between port 1 and port 2. Note that either port may be left free to atmosphere, rather than being connected to some preselected reference pressure.

regards

jack