Model 31s have one sensor, Model 33s have two. And, they're intrinsically safe. Every 30 series instrument is tested and calibrated in an environmental chamber, duplicating field conditions. Last, but not least, a single 9V battery provides 90 hours of continuous operation. Specifications Pressure Specifications are for one year and include all effects of linearity, hysteresis, repeatability, and temperature.
Installed sensor depends on model.
See ordering information below.