Gas analyzer

Claim 2

Apparatus for use in sampling and analyzing a gas, comprising, in combination; a housing; sensing means in said housing and responding to sampled amounts of said gas to provide a detectable indication that is a function of the concentration of at least part of said sampled amount of gas; and a sampling head connected to said housing and adapted to be disposed between said housing and a source of gas to be analyzed to provide said sampled amounts of gas to said sensing means, said sampling head including a first elongated tubular member having an open end and an aperture spaced from said open end, said aperture providing a passage through which gas to be analyzed may be conducted to the interior of said member, a second elongated tubular member coaxially mounted with a close fit in said first member and extending from adjacent said aperture through said open end to provide a passageway for conduction of said gas from the interior of said first tubular member toward said sensing means; and flow restriction means coaxial with said first member and extending from adjacent said aperture into and coaxial with said second tubular member to restrict flow of said gas from said aperture into said second tubular member to a predetermined amount.

Claim 3

The apparatus of claim 1 wherein said flow restriction means and said second member are movable relative to each other between a first position in which said flow restriction means provides relatively restricted flow of said gas between said aperture and said second member, and a second position in which said flow is relatively free to permit clearing of said passageway of obstructions to flow therethrough.

Claim 4

The apparatus of claim 2 wherein said second member is slidably movable in said first member between said first and second positions.

Claim 5

The apparatus of claim 2 further including resilient biasing means connected between said flow restriction means and said second member for forcefully urging said flow restriction means and said second member into said first position.

Claim 6

The apparatus of claim 1 wherein the end of said first member opposite said open end is closed and said aperture is in a side wall of said first member and adjacent said closed end, and said second member extends in said first member away from said closed end and from closely adjacent said aperture and between said aperture and said open end, and said flow restriction means extends from between said closed end and said aperture into said second member at the end thereof adjacent said aperture, said flow restriction means terminating in said second member and forming an elongated annulus of a relatively small clearance with the inner wall of said second member, said annulus providing a passageway for the flow of said gas from said aperture into said second member.

Claim 7

The apparatus of claim 5 wherein each of said first and second members are straight cylindrical tubes of uniform diameter and have smooth wall surfaces.

Claim 8

The apparatus of claim 5 wherein said flow restriction means and said second member are movable relative to each between a first position in which said flow restriction means provides relatively restricted flow of said gas between said aperture and said second member, and a second position in which said flow is relatively free to permit clearing of said annulus from obstructions to flow therethrough.

Claim 9

The apparatus of claim 7 wherein said second member is slidably movable in said first member between said first and second positions.

Claim 10

The apparatus of claim 7 further including resilient biasing means connected between said flow restriction means and said second member for forcefully urging said flow restriction means and said second member into said first position.

Claim 11

As a sub-combination, a sampling head for regulating the flow of sampled amounts of gas into an apparatus for sampling and analyzing such a gas, comprising: a first elongated tubular member having an open end and an aperture spaced from said open end, said aperture providing a passage through which gas to be analyzed may be conducted to the interior of said member; a second elongated tubular member coaxially mounted with a close fit in said first tubular member and extending from adjacent said aperture through said open end to provide a passageway for conduction of said gas from the interior of said first tubular member to the exterior thereof; and flow restriction means coaxial with said first tubular member and extending from adjacent said aperture into and coaxial with said second tubular member to restrict flow of said gas from said aperture into said second tubular member to a predetermined amount.

Claim 12

As a sub-combination, a sampling head for regulating the flow of sampled amounts of gas into an apparatus for sampling and analyzing such a gas, comprising: a first elongated tubular member having an open end and an aperture spaced from said open end, said aperture providing a passage through which gas to be analyzed may be conducted to the interior of said member; a second elongated tubular member coaxially mounted with a close fit in said first tubular member and extending from adjacent said aperture through said open end to provide a passageway for conduction of said gas from the interior of said first tubular member to the exterior thereof; and flow restriction means coaxial with said first tubular member and extending from adjacent said aperture into and coaxial with said second tubular member to restrict flow of said gas from said aperture into said second tubular member to a predetermined amount.

Claim 13

The sampling head of claim 10 wherein said flow restriction means and said second member are movable relative to each other from a first position in which said flow restriction means provides reLatively restricted flow of said gas between said aperture and said second member, and a second position in which said flow is relatively free to permit clearing of said passageway of obstructions to flow therethrough.

Claim 14

The sampling head of claim 11 wherein said second member is slidably movable in said first member between said first and second positions.

Claim 15

The sampling head of claim 11 further including resilient biasing means connected between said flow restriction means and said second member for forcefully urging said flow restriction means and second member into said first position.

Claim 16

The sampling head of claim 13 wherein said flow restriction means is rigidly connected to said first member and said biasing means is connected between said first and second members.

Claim 17

The sampling head of claim 10 wherein the end of said first member opposite said open end is closed and said aperture is in a side wall of said first member and adjacent said closed end, and said second member extends in said first member away from said closed end and from closely adjacent said aperture and between said aperture and said open end, and said flow restriction means extends from between said closed end and said aperture into said second member at the end thereof adjacent said aperture, said flow restriction means terminating in said second member and forming an elongated annulus of a relatively small clearance with the inner wall of said second member, said annulus providing a passageway for the flow of said gas from said aperture into said second member.

Claim 18

The sampling head of claim 15 wherein each of said first and second members are straight cylindrical tubes of uniform diameter having smooth wall surfaces.

Claim 19

THe sampling head of claim 15 wherein said flow restriction means and said second member are movable relative to each other between a first position in which said flow restriction means provides relatively restricted flow of said gas between said aperture and said second member, and a second position in which said flow is relatively free to permit clearing of said annulus from obstruction to flow therethrough.

Claim 20

The sampling head of claim 17 wherein said second member is slidably movable in said first member between said first and second positions.

Claim 21

The sampling head of claim 17 further including resilient biasing means connected between said flow restriction means and said second member for forcefully urging said flow restriction means and said second member into said first position.

Claim 22

The sampling head of claim 19 wherein said flow restriction means is rigidly connected to said first member and said biasing means is connected between said first and second members.

Claim 23

Apparatus for use in sampling and analyzing a gas comprising in combination: a source of electrical potential including a high voltage terminal providing a relatively high electrical voltage substantially near ground potential, and a low voltage terminal providing an electrical voltage that is low with respect to said high voltage; a housing; means pervious to light mounted in said housing and forming an ionization chamber; two spaced-apart electrodes, each on opposite sides of said chamber, one of said electrodes being connected to said high voltage terminal and the other of the electrodes being connected to said low voltage terminal; an effectively grounded gas inlet in said housing adjacent said one electrode and in communication with the interior of said chamber to permit gas to pass from said inlet past said one electrode and into said chamber; and a sampling head connected to said inlet for regulating the flow of gas into said chamber, said sampling head including a first elongated tubular member having an open end and an aperture spaced from said open end, said aperture providing a passage through which gas to be analyzed may be conducted to the interior of said member, a second elongated tubular member coaxially mounted with a close fit in said first tubular member and extendinG from adjacent said aperture through said open end to provide a passageway for conduction of said gas from the interior of said first tubular member to said inlet, and flow restriction means coaxial with said first member and extending from adjacent said aperture into and coaxial with said second tubular member to restrict flow of said gas from said aperture into said second tubular member to a predetermined amount.

Claim 24

Apparatus for use in sampling and analyzing a gas comprising in combination: a source of electrical potential including a high voltage terminal providing a relatively high electrical voltage substantially near ground potential, and a low voltage terminal providing an electrical voltage that is low with respect to said high voltage; a housing; means pervious to light mounted in said housing and forming an ionization chamber; two spaced-apart electrodes, each on opposite sides of said chamber, one of said electrodes being connected to said high voltage terminal and the other of the electrodes being connected to said low voltage terminal; an effectively grounded gas inlet in said housing adjacent said one electrode and in communication with the interior of said chamber to permit gas to pass from said inlet past said one electrode and into said chamber; and a sampling head connected to said inlet for regulating the flow of gas into said chamber, said sampling head including a first elongated tubular member having an open end and an aperture spaced from said open end, said aperture providing a passage through which gas to be analyzed may be conducted to the interior of said member, a second elongated tubular member coaxially mounted with a close fit in said first tubular member and extendinG from adjacent said aperture through said open end to provide a passageway for conduction of said gas from the interior of said first tubular member to said inlet, and flow restriction means coaxial with said first member and extending from adjacent said aperture into and coaxial with said second tubular member to restrict flow of said gas from said aperture into said second tubular member to a predetermined amount.

Claim 25

The apparatus of claim 21 wherein said one electrode is grounded and further including means connected to said source and responding to the electrical current between said electrodes to maintain said current at a substantially constant value.