摘要 |
PURPOSE:To detect the moisture accurately together with temperature, by converting the stretching force of a moisturesensitive stretching body into an electrical signal with a pressure sensor pellet as obtained when it stretches according to the moisture in an atmosphere to be measured while temperature is detected from changes in the resistance value with respect to at least one temperature of the pressure sensor pellet. CONSTITUTION:As a moisture-sensitive stretching body 9 of a pressure sensor pellet 1 stretches according to the moisture in contact with an atmosphere to be measured passing through a case opening 11, a diaphragm 10 is distorted and the resistance values of diffusion areas 4a-4d vary accordingly. The resistance value varies with temperature. When a changeover switch 70 is set to the contact position as indicated by the solid line, the resistance areas 4a-4d are connected in bridge with a moisture measuring section 50 to measure the moisture from the output V1 thereof. An offset adjustment and temperature compensation are done with resistances 51 and 52. On the other hand, when the switch 70 is set to the contact position as indicated by the broken line, the resistance areas are connected in series with a temperature measuring section 60 and a constant current is supplied from a DC power source 61 to measure the temperature from the terminal voltage V2.
|