Gas sensor with flashback barrier
AssigneeDrager Sicherheitstechnik GmbH
InventorsHorst Wezurek, Hans-Jürgen Bahs
Life of this patent
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Abstract
An explosion-proof gas sensor (1) with a flashback barrier (2) permeable to the gas to be measured between the measuring space (4) and the environment in an otherwise gas-impermeable housing (3) is described. The sensor provides reduced response time and higher signal sensitivity for the gas to be measured. A flashback barrier (2) is provided including a plurality of flexurally rigid fabric layers made preferably of metal, which are permeable to the gas to be measured, with an overall thickness of one to ten mm, an overall porosity of at least twenty percent by volume relative to the volume of the flashback barrier (2), and with a maximum number of one percent of all pores with a pore size larger than 240 μm.
Claims20
A gas sensor arrangement comprising:
- a gas-impermeable housing defining a measuring space;
- and
- a flashback barrier permeable to the gas to be measured disposed between the measuring space and the environment to provide a gas permeable area in the otherwise gas-impermeable housing, said flashback barrier including a plurality of flexurally rigid fabric layers permeable to the gas to be measured, said barrier having an overall thickness of one to ten mm with an overall porosity of at least twenty percent by volume relative to the volume of said flashback barrier and with a maximum percentage of pores with a pore size larger than 240 μm equal to one percent.
A process of measuring the concentration of hydrocarbons, the process comprising, the steps of:
- providing a gas-impermeable housing defining a measuring space;
- providing a flashback barrier permeable to the gas to be measured disposed between the measuring space and the environment to provide a gas permeable area in the otherwise gas-impermeable housing, said flashback barrier including a plurality of flexurally rigid fabric layers permeable to the gas to be measured, said barrier having an overall thickness of one to ten mm with an overall porosity of at least twenty percent by volume relative to the volume of said flashback barrier and with a maximum percentage of pores with a pore size larger than 240 μm equal to one percent;
- providing a measuring element in the measuring space;
- and
- measuring the concentration of hydrocarbons that enters the measuring space from the environment.
A gas sensor comprising:
- a gas-impermeable housing defining a measuring space;
- a measuring element disposed in said measuring space;
- and
- a flashback barrier permeable to the gas to be measured disposed between the measuring space and the environment to provide a gas permeable area in the otherwise gas-impermeable housing, said flashback barrier including a plurality of flexurally rigid fabric layers permeable to the gas to be measured, said barrier having an overall thickness of one to ten mm with an overall porosity of at least twenty percent by volume relative to the volume of said flashback barrier and with a maximum percentage of pores with a pore size larger than 240 μm equal to one percent.
Dependencies are inferred from the claim text.