New sensor developments

Abstract

The new sensors are the result of new materials, techniques, and calculation and decision capabilities. They are more accurate, reliable, rugged, noncontacting and digital. A microprocessor is integrated with nearly every sensor system, giving both local and milewide access to all information. Many of the new sensors are basic in function — smell, taste, tactile, machine vision, and sound. For example, new odor meters indicate temperature rise as the odorous gas oxidizes or due to an electrode conductivity changes; guidelines are established for quality standards or acceptable odor levels. Or the outputs from several sensors of variables associated with the flavor of liquid are combined in a trial and error relationship until a satisfactory correlation is achieved by artificial intelligence. Thin-film sensors for tactile measurements are based upon electrical conductivity changes with pressure; microprocessor scanning of electrodes results in a quick display of sensitive field-effect transistor pH meter for a drop of sample; chemical environmental sensors; and a micro-gas chromatograph. Fast Fourier Transforms (FFT) applied to a Doppler flowmeter enhance the speed and sensitivity by a factor of ten. Self-calibrating sensors with corrections for either variables include a new radiometer with laser-corrected emissivity and a self-calibrating fiber optic temperature sensor insensitive to emissivity. Infrared photoacoustic sensing is the newest generation of advanced technology sensors for gas analysis, and it results in a most stable zero and span. Other noteworthy new products include hybrid photodetectors, solid-state toxic gas detectors, ultrasonic and microwave radar level and distance gages, microminiature color camera, color scanner, surface quality meter, and multi-wave length spectral analyzers.