Gaseous detection system

A gas detection system for detecting the presence of and determining the level of a preselected gas, the system comprising:

• (a) sensing means for sensing the preselected gas, said sensing means including isolation means having an input for receiving a mixture of gases at a substantially constant pressure, and an output for providing a sequential flow of substantially segregated gases, such that the preselected gas as contained within said mixture of gases will be provided in substantially isolated form at said output during a preselected window of time following introduction of said mixture of gases to said input;
• (b) means for providing a signal when said preselected gas is sensed;
• wherein said sensing means further includes:
• a sensor responsive to preselected gas and which provides an electric signal in response thereto;
• a first pneumatic pathway connected in series with said sensor;
• a second pneumatic pathway connected in parallel to said first pathway with said sensor;
• and
• valve means for controlling said sequential flow of substantially segregated gases from said isolation means with respect to said first and second pneumatic pathways.

A gas detection system for detecting the presence of and determining the level of a preselected gas, the system comprising:

• (a) sensing means for sensing the preselected gas, said sensing means including isolation means having an input for receiving a mixture of gases at a substantially constant pressure, and an output for providing a sequential flow of substantially segregated gases, such that the preselected gas as contained with said mixture of gases will be provided in substantially isolated form at said output during a preselected window of time following introduction of said mixture of gases to said input;
• (b) means for providing a signal when said preselected gas is sensed;
• wherein said sensing means includes:
• a sensor for providing an electronic signal in response to being exposed to gases of interest;
• comparator means for comparing an output of said sensor with a reference value to determine presence of said gases of interest;
• and
• sample and hold means for forming said reference value as a function of said sensor's output.

(twice amended) A gas detection system for detecting the presence of and determining the level of a preselected gas, the system comprising:

• (a) sample means for obtaining samples of both ambient air, and suspect air possibly containing a preselected gas;
• (b) isolation means for receiving said suspect air from said sample means and substantially isolating the preselected gas at a substantially constant pressure from other gases therein, said isolation means subsequently receiving said ambient air from said sample means;
• (c) means for receiving ambient air from said sample means at the same time as said isolation means receiving said ambient air sample, whereby to obtain a reference value;
• (d) means for sensing said reference value;
• and
• (e) signal means for providing a signal in response to the sensing of said isolated preselected gas.

A method of detecting a preselected gas comprising the following steps:

• (a) sampling and measuring ambient air to create a first reference value;
• (b) sampling suspect air;
• (c) isolating a preselected gas, if present, from said sampled suspect air and measuring said isolated gas to create a second reference value;
• (d) comparing said isolated gas second reference value with said ambient air first reference value;
• (e) sensing the level of said isolated gas;
• and
• (f) generating a signal in response to said isolated gas level.

A method of detecting a preselected gas comprising the following steps:

• (a) sampling a first gas and generating a first reading therefrom;
• (b) sampling a first gas and generating a second reading therefrom;
• (c) comparing said first and second readings and obtaining a first evaluation therefrom;
• (d) sampling a suspect gas possibly containing said preselected gas and generating a third reading therefrom;
• (e) comparing said first and third readings and obtaining a second evaluation therefrom;
• and
• (f) generating a signal from said second evaluation.

An ethanol detection system for use in a vehicle having an interior compartment, the system comprising:

• (a) sensing means for sensing ethanol in the breath of an selected individual in gaseous form in said interior compartment of said motor vehicle and said sensing means including isolation means for having an input for receiving a mixture of gases from said interior compartment at a substantially constant pressure, and an output for providing a sequential flow of substantially segregated gases, such that ethanol gas as contained within said mixture of gases will be provided in substantially isolated form at said output during a preselected window of time following introduction of said mixture of gases to said input;
• (b) actuation means for providing an actuation signal when said sensed ethanol at least exceeds a preselected concentration level;
• wherein said sensing means further includes:
• a first exhaust outlet;
• a second exhaust outlet;
• and
• a first valve means operably connected to said isolation means and said first and second exhaust outlets for selectively connecting said output of said isolation means to said first and second exhaust outlets.

A system for detecting the presence and level of a preselected gas, the system comprising:

• a first pneumatic pathway for transmitting a first gas;
• a second pneumatic pathway for transmitting either a first gas or a gas suspected of containing the preselected gas;
• first means for developing a profile of said first gas;
• second means for developing a profile of either said first gas or of said suspect gas;
• sensor means for simultaneously evaluating and comparing said first gas from both said first and second pathways and generating a first reading therefrom, said sensor means subsequently evaluating and comparing said first gas from said first pathway with said suspect gas from said second pathway and generating a second reading therefrom;
• and
• means responsive to said first reading and to said second reading for generating indicia of the presence and level of said preselected gas.