Process for interrogation of a detector of the concentration of combustible gas and an implementing device

Claim 1

A process for interrogating a detector of the concentration of combustible gas supplying a polarized unbalancing signal comprising the steps of: (a) applying a first voltage to said detector for a first time period of an interrogation sequence, wherein said first voltage is cut upon detection of a positive signal from said detector; (b) applying a second voltage, higher than said first voltage, to said detector for a second time period, but only if the signal from said detector has been less than or equal to zero during said first time period; and (c) measuring the signal produced by said detector when said second voltage is applied against a predetermined maximum value and a predetermined minimum value.

Claim 5

A device for detecting the concentration of a combustible gas in an atmosphere comprising: (a) means for alternately producing a first voltage and a second voltage, wherein said first voltage is lower than said second voltage; (b) means for detecting the concentration of said combustible gas in said atmosphere, wherein said detecting means is coupled with said producing means and emits a polarized unbalancing signal in response to said combustible gas and an applied voltage; (c) means for comparing said polarized unbalancing signal with a predetermined minimum signal amplitude and a predetermined maximum signal amplitude; and (d) means for stopping said first voltage from being further applied if said polarized unbalancing signal produced in response to said first voltage is not within a predetermined range and for stopping said second voltage from being applied to said detecting means if said polarized unbalancing signal produced in response to said first voltage is not within a predetermined range.

Claim 6

A device for detecting the concentration of a combustible gas in an atmosphere comprising: (a) means for alternately producing a first voltage and a second voltage, wherein said first voltage is lower than said second voltage; (b) means for detecting the concentration of said combustible gas in said atmosphere, wherein said detecting means is coupled with said producing means and emits a polarized unbalancing signal in response to said combustible gas and an applied voltage; (c) means for comparing said polarized unbalancing signal with a predetermined minimum signal amplitude and a predetermined maximum signal amplitude; and (d) means for stopping said first voltage from being further applied if said polarized unbalancing signal produced in response to said first voltage is not within a predetermined range and for stopping said second voltage from being applied to said detecting means if said polarized unbalancing signal produced in response to said first voltage is not within a predetermined range.

Claim 7

A device for detecting the concentration of a combustible gas in an atmosphere comprising: (a) a voltage reducing circuit capable of producing a first voltage and a second voltage, higher than said first voltage; (b) a power source coupled with said voltage reducing circuit; (c) timing means for first applying said first voltage for a first time period and then applying said second voltage for a second time period; (d) a detector coupled with said voltage reducing circuit that produces a polarized unbalancing signal in response to said voltage reducing circuit and the presence of said combustible gas; (e) an amplifier coupled with said detector that amplifies said polarized unbalancing signal; (f) a discriminator coupled with said amplifier that compares said amplified polarized unbalancing signal to a predetermined maximum and minimum; and (g) means for controlling said voltage reducing circuit coupled with said voltage reducing circuit and coupled with said discriminator, wherein said controlling means prevents said first voltage from being applied for the entirety of said first time period if said polarized unbalancing signal produced in response to said voltage reducing circuit and said combustible gas during said first time period is not within a predetermined range and wherein said controlling means further prevents said second voltage from being applied to said detector if said polarized unbalancing signal produced in response to said voltage reducing circuit and said combustible gas during said first time period is not within a predetermined range.

Claim 8

A device for detecting the concentration of a combustible gas in an atmosphere comprising: (a) a voltage reducing circuit capable of producing a first voltage and a second voltage, higher than said first voltage; (b) a power source coupled with said voltage reducing circuit; (c) timing means for first applying said first voltage for a first time period and then applying said second voltage for a second time period; (d) a detector coupled with said voltage reducing circuit that produces a polarized unbalancing signal in response to said voltage reducing circuit and the presence of said combustible gas; (e) an amplifier coupled with said detector that amplifies said polarized unbalancing signal; (f) a discriminator coupled with said amplifier that compares said amplified polarized unbalancing signal to a predetermined maximum and minimum; and (g) means for controlling said voltage reducing circuit coupled with said voltage reducing circuit and coupled with said discriminator, wherein said controlling means prevents said first voltage from being applied for the entirety of said first time period if said polarized unbalancing signal produced in response to said voltage reducing circuit and said combustible gas during said first time period is not within a predetermined range and wherein said controlling means further prevents said second voltage from being applied to said detector if said polarized unbalancing signal produced in response to said voltage reducing circuit and said combustible gas during said first time period is not within a predetermined range.