A meter relay in which the mechanical contacts on the meter of a mechanically operating type of relay are replaced by solid state circuitry. The circuitry is readily adjustable by a simple potentiometer of rheostat to operate an indicating signal and/or a control for industrial apparatus or the like at any desired point over the entire range of a meter. The circuitry is operative, however with or without a meter. A plurality of identical circuits mounted on separate panels or modular units may be ganged to operate different indicators and/or controls at a plurality of points over the range of one or more relay meter devices.
A digital multimeter having a tone generating circuitry and operable in a tone mode of operation for providing an audible indication when a measured electrical characteristic has a predetermined relationship with a reference value. The audible indication may be provided when a voltage level exceeds a preselectable limit, such as 1 or 2 volts. Predetermined limits for resistance values may also be selected for actuation of the audible tone. The device may be utilized as a conventional multimeter when the tone mode is non-operative.
