SEMICONDUCTOR GAS SENSOR Russian patent published in 2016 - IPC G01N27/12 

FIELD: instrument making.

SUBSTANCE: invention can be used in gas analysers, gas analysers and gas fire detectors for monitoring pre-explosion concentration of explosion-inflammable gases and gas mixtures. Semiconductor gas sensor comprises a body of reaction chamber made of stainless steel and closed end face mesh of stainless steel wire with diameter 0.02…0.05 mm with spacing of 0.05…0.07 mm. In housing in centre of reaction chamber on contact conductors (4) spherical semiconductor gas-sensitive element (5) of sensor by means of wires of heater (6) and measuring conductor (7). Inside semiconductor gas-sensitive element (5) of heater (6) in form of cylindrical spring inside which along its axis and along diameter of spherical semiconductor element (5) there is direct measuring conductor (7). Heater (6) and measuring conductor (7) of gas-sensitive element (5) are made from platinum wire with diameter 0.01…0.025 mm, heater (6) has 3…15 wire coil, spherical semiconductor gas-sensitive element (2) has external diameter of 0.4…0.8 mm and is made from internal volume (8): SnO₂ - 40…60 wt.%, and external volume (5) of porous gamma-Al₂O₃ - 40…60 wt%, respectively, spherical gas sensing element of sensor. Heater (6) is adapted to supply a constant voltage of 0.2…1.5 V.

EFFECT: invention provides considerable improvement of long-term stability, ease of manufacture of sensor, as well as high sensitivity of semiconductor gas sensor to small concentrations of gases, efficiency and resistance to external factors.

1 cl, 1 tbl, 10 dwg