a small radio transmitter inserted into a pipe

A small transmitter that emits electromagnetic energy at a specific frequency. This device is pushed into a pipe or duct by means of a rod, and its location is found by means of a receiver. These devices are often used to find faults in sewer pipes. Sondes that emit signals at the lower frequencies may used to locate faults in pipes of cast iron. The term is an abbreviation of Radio Sonde.

drilling equipment – The downhole component of an electronic locating system. Same as a transmitter.

That which is sent; a message or messenger; hence, also, a visitation of providence; an affliction or trial.

a rocket or balloon sent into the upper atmosphere to measure atmospheric conditions or other phenomena at altitudes unattainable by aircraft.

is a device sent up into the air, typically borne on a balloon, to obtain information about atmospheric conditions. Radiosondes, for example, measure temperature, pressure and humidity and then "radio" or transmit these data to Earth.

Sonde is a music design and performance ensemble based in Montreal. From 1975 to about 1985, Sonde gave hundreds of performances in North America and Europe on sound sources of their own invention. Sonde was also engaged in television, film, and dance (particularly contact improvisation).

a well logging tool.

a device that measures and transmits physical information