This read-only value identifies the type of physical quantity that the associated entPhySensorValue reports, such as temperature, voltage, or RPM, and is set once by the agent at entry creation and does not change afterward. Admins use it to know how to interpret a given sensor's raw value before displaying or alarming on it. For example, an entPhySensorType of celsius tells the admin the paired entPhySensorValue reading is a temperature in degrees Celsius rather than, say, a voltage.