PYROELECTRIC ANEMOMETER

摘要

Disclosed is a pyroelectric anemometer capable of providing an accurate indication of fluid flow rate. A pyroelectric substrate has a heater element located essentially transverse to the fluid flow direction. Sensor electrodes also transverse to the fluid flow direction are located upstream and downstream of the heater electrode. A fluctuating power supply is connected to the heater electrode which results in a fluctuating voltage at each sensor electrode. The amplitude of the fluctuations at the electrodes are compared and the difference in amplitude of fluctuations is indicative of the flow rate of fluid flowing thereover. Preferred embodiments utilize a differential amplifier to compare the fluctuating amplitudes and provides an output to a lock-in-amplifier which provides a fluid flow rate indicator output.