GB749514A - Apparatus for measuring and recording the magnitude of a variable condition - Google Patents

Abstract

749,514. Electric indicating systems. BRITISH PEROLEUM CO., Ltd., [formerly ANGLO-IRANIAN OIL CO. Ltd.]. Jan. 20, 1954 [Feb. 26, 1953]. No. 5407/53. Class 40(1) [Also in Group XIX] A variable magnitude is periodically recorded by driving an electric motor in the appropriate direction according to the magnitude and sense of changes in the variable, the motor driving a printing counter which records through an inked ribbon on a continuously driven paper tape at each energization of a periodically operated solenoid. As shown, the variable resistance arm 12 of a bridge may comprise a platinum resistance thermometer or the slider of the resistance may be adjusted by a mechanical link 10 in accordance with temperature, pressure or other variable. The bridge output is balanced automatically by the output potential of a potentiometer 21 adjusted by a motor 19 responsive to the difference of the two outputs, after amplification at 17 and phase sense rectification at 18. The motor drives a counter 22 the reading of which is periodically impressed on a tape 26, driven with an ink ribbon 25 by clockwork 27 or a second motor, by a solenoid 28 operated e.g. by contacts closed by the clockwork. The invention may be used for measuring temperature and or pressure in bore-holes in which case the oscillator 14 feeding the bridge supply batteries and the various other elements of Fig. 1 are located in a tubular casing.