Abstract: A method of and device for calibrating infrared radiation transducers. A concentration factor representing the ratio of a data signal to a reference signal for a known concentration of a designated gas in a sample containing that gas is generated. The concentration factor is stored and used during subsequent calibration procedures. The calibration device has a zero cell and a span cell with windows for transmitting infrared radiation and radiation reflecting or absorbing material in the span cell. The span cell therefore provides a known and consistent level of radiation absorption.

Abstract: Gas analyzers of the non-dispersive infrared radiation type which are designed to measure the concentration of one gas in a mixture of gases containing that gas. An infrared radiation emitter is employed to emit energy at a frequency of 40-100 Hz with a system which includes a source driver and a timer; and a detector is used to intercept the attenuated beam after it has passed through the mixture being analyzed and output a signal indicative of the concentration of the selected gas. Also, a second detector is preferably provided so that a ratioed, error eliminating output signal can be supplied to the failsafe, signal processing circuitry of the analyzer. The detectors are electrically biased by way of flyback transformer based circuitry to improve the signal-to-noise ratio, and the signal processing circuitry can be adjusted to compensate for drift. The detectors are mounted on a thermally conductive substrate along with appropriate filters, a filter frame, and a cover.

Abstract: Gas analyzers of the non-dispersive infrared radiation type which are designed to measure the concentration of one gas in a mixture of gases containing that gas. A novel, electrically modulated, stable, thick film infrared radiation emitter is employed to emit a beam of collimated, focused energy; and two electrically biased detectors are preferably used so that a ratioed, error eliminating output signal can be supplied to the failsafe, signal processing circuitry of the analyzer. The latter, and a conventional analog-to-digital convertor, supply information to a microcomputer which: (1) turns the infrared radiation emitter on and off; (2) controls a heater which keeps the infrared radiation detectors at a constant, precise temperature; and (3) controls displays of a variety of information concerning the gas being measured and the status of the gas analyzer. The microcomputer also accepts ambient temperature, barometric pressure, and other compensation factors.

Abstract: Gas analyzers of the non-dispersive infrared radiation type which are designed to measure the concentration of one gas in a mixture of gases containing that gas. A novel, electrically modulated, stable, thick film infrared radiation emitter is employed to emit a beam of collimated, focused energy; and two electrically biased detectors are preferably used so that a ratioed, error eliminating output signal can be supplied to the failsafe, signal processing circuitry of the analyzer. The latter, and a conventional analog-to-digital convertor, supply information to a microcomputer which: (1) turns the infrared radiation emitter on and off; (2) controls a heater which keeps the infrared radiation detectors at a constant, precise temperature; and (3) controls displays of a variety of information concerning the gas being measured and the status of the gas analyzer. The microcomputer also accepts ambient temperature, barometric pressure, and other compensation factors.