Telemetering

(or telemetry), measurement at a distance through telemechanic means. The term “telemetering” is also applied to the branch of telemechanics that deals with the transmission of measurement information over distance and with the presentation of the information in a form suitable for direct human perception or for input into a control device or automatic recorder. The term “telemechanics,” as used in the present article, is similar in meaning to the English term “remote control” in its broadest sense (see).

In telemetering, measurement information is transmitted from transducers, or sensors, to a control or monitoring center continuously, cyclically, or, sometimes, on request (when the operator sends a special interrogation signal containing the address or coded designation of the measured parameter). A continuously measured quantity is often quantized at the monitored point (seeQUANTIZATION, SIGNAL). At the control center, the value of the quantity may be displayed in analogue form (as readings of movable-pointer indicators) or in digital form. Measurement information may be transmitted by means of telemetering systems, combined telemetering and remote-signaling systems, or more complex telemechanic systems.

The term “radio telemetry” is applied to telemetering involving the use of radio channels (seeRADIO REMOTE CONTROL).