It measures the pressure in 1/1000th of an inch of Mercury, which can easily be converted other units like Pascal and PSI. The temperature is measured in 1/10th degrees Celcius.
I already have a driver and test program for it and I’ll be sure to release it very shortly with the next version of the driver suite.
You know, if you were to combine this sensor with the Angle Sensor, you could put some of those excavator scoops on and make an anemometer to complete the weather station! Just be sure to keep it out of the rain.