Abstract: In a power sensor for RF power measurments, comprising a thin-film absorbing resistor formed on the top surface of a support member and a thermocouple which is electrically isolated from the circuit of said absorbing resistor, the absorbing resistor is formed on an insulating film of a silicon support member so as to increase the sensitivity and to facilitate manufacture thereof, the silicon support member including an island formed beneath the absorbing resistor, a thermally conducting portion formed in spaced relationship thereto with a narrow bridge portion provided inbetween, and said thermocouple being constituted by the bridge portion and by mutually spaced contact zones formed thereon.

Abstract: In a sound level meter the output voltage of the microphone is fed to a voltage-frequency converter by way of an exponentially operating circuit, such as a squarer, and the output of the converter operates a binary counter having an indicator unit associated therewith. A gate circuit is controlled by a timing generator and is interposed between the voltage-frequency converter and the binary counter. The indicator unit includes a plurality of indicating elements which are connected at the outputs of the successive counter stages and each of the indicator elements is associated with a particular indicia carried on a dB scale. With a squarer as the exponential circuit the dB scale has a 3 dB incrementation for the respective indicator elements.