Ferroelectric thermometry and pyrometry by active operation

1. Field of the Invention A ferroelectric/pyroelectric sensor that employs a technique for determining a charge output of a pyroelectric element of the sensor by measuring the hysteresis loop output of the element several times during a particular time frame for the same temperature. An external AC signal is applied to the pyroelectric element to cause the hysteresis loop output from the element to switch polarization. Charge integration circuitry, such as a combination capacitor and operational amplifier, is employed to measure the charge from the element. A mechanical shutter is not used, and thus the charge integration output from the element is directly proportional to the incident radiation thereof.