Abstract: An instrument is provided for measuring the temperature of an object from infrared radiation emitted by the object. The instrument includes a radiation detector, a temperature indicating device connected to the detector, and a modulator disposed in a path of a radiation beam from the object for converting the beam into a series of pulses when the modulator is vibrated in and out of the path. The modulator includes a primary piezoelectric element adapted to vibrate when subjected to driving signals at a frequency related to the resonant frequency of the modulator, and a secondary piezoelectric element connected with and driven by the primary piezoelectric element. The secondary piezoelectric element is electrically insulated from the primary piezoelectric element. The modulator also includes a blocking element connected with the secondary piezoelectric element and disposed to move in and out of the path of the beam.

Abstract: A method and apparatus are described for measuring the amplitude of radiation emitted by an object and compensating for the effects of ambient temperature fluctuations. A radiation sensor is provided receiving radiation from the object and converting it into an alternating current sensor output signal. A thermal sensor detects an ambient temperature proximately to the radiation sensor and generates an alternating current compensation signal having an amplitude proportional to the ambient temperature. A summing amplifier coupled to the radiation sensor and the thermal sensor combines the sensor output signal from the radiation sensor and the compensation signal from said thermal sensor to form an alternating current output signal. The amplitude of the alternating current output signal is proportional to the amplitude of radiation emitted by the object and excludes the effect on the instrument by the ambient temperature.

Abstract: An instrument is provided for measuring the temperature of an object from infrared radiation emitted by the object. The instrument includes a radiation detector, a temperature indicating device connected to the detector, and a modulator disposed in a path of a radiation beam from the object for converting the beam into a series of pulses when the modulator is vibrated in and out of the path. The modulator includes a primary piezoelectric element adapted to vibrate when subjected to driving signals at a frequency related to the resonant frequency of the modulator, and a secondary piezoelectric element connected with and driven by the primary piezoelectric element. The secondary piezoelectric element is electrically insulated from the primary piezoelectric element. The modulator also includes a blocking element connected with the secondary piezoelectric element and disposed to move in and out of the path of the beam.

Abstract: An instrument is provided for measuring the temperature of an object from infrared radiation emitted by the object. The instrument includes a radiation detector, a temperature indicating device connected to the detector, and a modulator disposed in a path of a radiation beam from the object for converting the beam into a series of pulses when the modulator is vibrated in and out of the path. The modulator includes a primary piezoelectric element adapted to vibrate when subjected to driving signals at a frequency related to the resonant frequency of the modulator, and a secondary piezoelectric element connected with and driven by the primary piezoelectric element. The secondary piezoelectric element is electrically insulated from the primary piezoelectric element. The modulator also includes a blocking element connected with the secondary piezoelectric element and disposed to move in and out of the path of the beam.

Abstract: A system is provided in which oral sounds are converted to instrumental musical notes. The system includes a digital memory adapted to store notes of different instruments and of different timbre. A variable address generator connected to the memory is adapted to retrieve the notes at various addressing rates in order to change the pitch thereof. The system is adapted to generate musical instrument output sounds in response to an oral input over a whole range of notes including pitches between whole and half tone increments in an unbroken frequency spectrum of pitch.

Abstract: A thermometer is provided for remotely measuring the temperature of a heat source. The device utilizes an infrared sensor for detecting the temperature of a remote object and an output of the sensor is processed and used to drive a meter or other display device. An improved resonant circuit is provided for modulating the radiant energy impinging on the sensor to produce a pulsed output from the sensor. The modulating circuit includes a piezoelectric reed which deflects under an applied frequency and is located in the optical path of the system. The reed serves as an active element in an improved phase-locked loop used to drive and stabilize the optical chopper.