Apparatus for detecting or measuring a constituent of a gas
OwnerThomas Parry Jones, Basil Martin Wrightinventors
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Abstract
Apparatus for detecting alcohol vapour in a gas, such as exhaled breath. The apparatus comprises a detachable mouthpiece through which a person exhales. The mouthpiece includes a vent for venting some exhaled breath to atmosphere and an outlet port connected to a sensor which provides an electrical output dependent upon the amount of alcohol in the breath sample. A piston and cylinder valve assembly is provided for introducing a predetermined amount of the sample into the sensor at a time dictated by an operator. A calibrated meter, which may be analogue or digital is connected to the sensor to indicate the amount of alcohol in the sample.
Claims9
Apparatus for detecting alcohol vapour in a gas and particularly for detecting alcohol vapour in exhaled breath, comprising a fuel cell, said fuel cell having inlet means for interposition in an intermediate position of a low resistance path along which breath is exhaled, said low resistance path comprising a tube including an inlet for receiving said gas, a first outlet for detachable connection to the inlet means and a vent port for venting at least some of the gas to atmosphere, means serially communicating with said inlet means through said fuel cell and actuable for drawing a predetermined sample volume of gas from the exhaled breath stream into said fuel cell, said fuel cell further including means for providing an electrical output signal dependent upon the amount of alcohol vapour in the gas sample, and measuring means coupled to the sensor output for measuring the magnitude of said electrical output signal.
Apparatus for detecting alcohol vapour in a gas and particularly for detecting alcohol vapour in exhaled breath, comprising a fuel cell, said fuel cell having inlet means for interposition in an intermediate position of a low resistance path along which breath is exhaled, means serially communicating with said inlet means through said fuel cell and actuable for drawing a predetermined sample volume of gas from the exhaled breath stream into said fuel cell, said drawing means comprising a cylinder, a piston slidably mounted in the cylinder, a gas communicating means connected between the cylinder and fuel cell, and resilient means for biasing the piston in one direction, said fuel cell further including means for providing an electrical output signal dependent upon the amount of alcohol vapour in the gas sample, and measuring means coupled to the sensor output for measuring the magnitude of said electrical output signal.
In apparatus for detecting alcohol vapour in a gas including a sensor for providing an electrical output signal dependent upon the amount of alcohol present in a gas sample introduced into it;
- and means introducing a predetermined volume of a gas sample into the sensor comprising,
- a cylinder having a gas port formed therein, a gas communicating means connecting between the gas port and a port in the sensor,
- a piston slideably mounted in said cylinder between first and second limiting positions, and means resiliently biasing the piston towards said second position,
- latch means for maintaining the piston in its first position against the bias of the resilient means, and
- means for releasing the latch means and thereby for introducing the said predetermined volume of gas into the sensor as the piston is moved to its second position by said resilient means.
Dependencies are inferred from the claim text.