AUTOMATIC CONTROL DEVICE FOR METHANE AND OTHER COMBUSTIBLE GASES Russian patent published in 1994 - IPC

FIELD: gas industry. SUBSTANCE: device has thermocatalytic bridge sensor 6, amplifier is connected across a diagonally opposite pair of bridge sensor junctions. Amplifier output is connected to rectifier bridge which output is connected to analog methane concentration indicating instrument via resistor 9, voltage-to-frequency convertor, diagnosis control unit, methane ultimate concentration comparator, audible signalling unit, unit 1 computing gas momentary concentration, gas integral concentration and gas concentration indication correction value. Device also has fixed storage 2, nonvolatile storage 3, digital display unit 4, serial interface modulator 5, frequency detector data digital processing unit 9, input circuit opto isolating unit 7. Inputs of unit 7 are connected to outputs of frequency detectors , outputs of unit 7 are connected to input of unit 9 via multiplexer 8. Control inputs of unit 9 are connected to outputs of port P1 of unit 1. Device also has frequency oscillator 10 with programmable frequency divider which control inputs are connected to outputs of ports P1 and P2 of unit 1. Output of oscillator 10 is connected to input of output circuit opto isolating unit 12 via demultiplexer 11. Outputs of unit 12 are connected to frequency filters 13.1-13.8 which outputs are connected to detector inputs via power network. Besides device has power unit 14 which first a. c. voltage output is connected to choke filters. Choke filters outputs are connected to detectors inputs. Device also has executive unit 15 and audible signalling unit 16 which outputs are connected to outputs of port P2. EFFECT: higher reliability. 4 cl, 10 dwg