Microelectronic humidity–frequency transducer with humidity-sensitive capacitive elements

Abstract

A microelectronic transducer with capacitive elements implementing the principle of humidity to frequency conversion has been developed. Experiments has been conducted for samples of Р14 Rapid humidity-sensitive capacitors (Wired and SMD) of Innovative sensor technology company, HСH-1000 humidity-sensitive capacitors of Honeywell company, and humidity-sensitive MOS capacitor of Helium Research Institute ((Vinnytsya, Ukraine). The essential effect of the physical and chemical properties of the humidity-sensitive layer of the capacitive element on the sensitivity of the humidity–frequency transducer has been experimentally proved. In a range of 18–99% of humidity, the transducer with a humiditysensitive MOS capacitor based on amorphous silicon has the highest sensitivity of 3500 Hz/%. The range of change in the oscillation frequency is 320 kHz.