Discusses three types of sensors; pressure, gas detection, and relative humidity. Explains their use for laboratory measurements of gas pressure and detection of specific gaseous species. Shows diagrams of devices and circuits along with examples and applications including microcomputer interfacing. (RT)

Describes an interface that uses semiconductor metal oxides to detect low gas concentrations. Notes the detector has long life, high stability, good reproducibility, low cost, and is able to convert the gas concentration to an electrical signal with a simple circuit. Theory, schematic, and applications are provided. (MVL)

Describes direct and indirect voltage input techniques and their applications to voltage measurements with a microcomputer. Details circuitry that can be used for this with a gameport. Gives examples of circuit modifications, application of voltage measurement, and alternatives to this method. (CW)