Method of operating a gas analyzer and solid electrolyte gas sensing apparatus

Claim 2

In a method for operating a gas analyzer apparatus including the steps of venting flowing reference gas and equalizing the pressure of said flowing reference gas environment and a monitored gas environment disposed in contact with either side of a gas measuring electrochemical cell mounted in a support member defining said reference gas environment, said support member being received in a tubular shield member, an annular chamber being defined therebetween, and including a porous seal separating the annular chamber from the monitored gas environment; the improvement to said method comprising the steps of: venting the flowing reference gas from the reference gas environment in the support tube into the annular chamber at a venting location sufficiently close to the electrochemical cell to make the gas pressure of the reference gas environment substantially equal to the gas pressure of the monitored gas environment, said venting location being selected to prevent the vented reference gas from affecting the measurement of the monitored gas environment by said electrochemical cell; adjusting the flowing reference gas flow rate to provide a difference in gas pressure between the reference gas environment and the monitored gas environment which difference corresponds to a pressure drop established by said venting location; and purging both said annular chamber and said porous seal of gas from the monitored gas environment with said vented flowing reference gas.

Claim 3

In an in-situ gas analyzer apparatus having reference gas vent means to vent a flowing reference gas from a reference gas environment to a monitored gas environment, the improvement wherein said gas analyzer apparatus comprises: an electrochemical cell for generating an electrical signal in either a voltage mode or a current mode indicative of a gas constituent of interest of a monitored gas environment on the basis of a difference in the partial pressure of the gas constituent of the monitored gas environment contacting one surface of the electrochemical cell and that of the flowing reference gas environment contacting the opposite surface of the electrochemical cell; a tubular support means; a packing gland means securing said electrochemical cell within said tubular support means, said gland means being substantially resistant to gas flow therethrough, while resiliently accommodating mechanical stress between said cell and said tubular support means, said gland means separating said reference gas environment within said tubular support means from said monitored gas environment at said cell; a housing portion having securing means therein for retaining the tubular support means within said housing portion; said housing portion having an aperture therein defining the reference gas vent means, said aperture being in communication with said tubular support means at a location sufficiently close to the cell to make the gas pressure of the reference gas environment substantially equal to the gas pressure of the monitored gas environment; and means for maintaining a reference gas flow rate such that gas pressure difference between the reference gas environment and monitored gas environment across said cell is substantially equal to the pressure drop across said reference gas vent means.

Claim 4

In an in-situ gas analyzer apparatus having reference gas vent means to vent a flowing reference gas from a reference gas environment to a monitored gas environment, the improvement wherein said gas analyzer apparatus comprises: an electrochemical cell for generating an electrical signal in either a voltage mode or a current mode indicative of a gas constituent of interest of a monitored gas environment on the basis of a difference in the partial pressure of the gas constituent of the monitored gas environment contacting one surface of the electrochemical cell and that of the flowing reference gas environment contacting the opposite surface of the electrochemical cell; a tubular support means; a packing gland means securing said electrochemical cell within said tubular support means, said gland means being substantially resistant to gas flow therethrough, while resiliently accommodating mechanical stress between said cell and said tubular support means, said gland means separating said reference gas environment within said tubular support means from said monitored gas environment at said cell; a housing portion having securing means therein for retaining the tubular support means within said housing portion; said housing portion having an aperture therein defining the reference gas vent means, said aperture being in communication with said tubular support means at a location sufficiently close to the cell to make the gas pressure of the reference gas environment substantially equal to the gas pressure of the monitored gas environment; and means for maintaining a reference gas flow rate such that gas pressure difference between the reference gas environment and monitored gas environment across said cell is substantially equal to the pressure drop across said reference gas vent means.

Claim 5

The gas analyzer apparatus according to claim 2 wherein the packing gland means comprises saffil wool and zirconium oxide powder fused therein.

Claim 6

The gas analyzer apparatus according to claim 2, wherein the reference gas vent means is defined by an aperture in said housing portion and said securing means.

Claim 7

The improved gas analyzer apparatus according to claim 2 including an outer tubular member extending from the housing portion and mounted in a spaced relation about said tubular support means, defining therebetween a test gas conduit adapted to deliver test gas to the process gas environment side of said electrochemical cell.

Claim 8

The gas analyzer apparatus according to claim 5 including test gas supply means in communication with the test gas conduit for delivering test gas to the process gas environment side of the electrochemical cell.

Claim 9

The gas analyzer apparatus according to claim 6 wherein the securing means isolates the reference gas vent means from the test gas conduit.

Claim 10

The gas analyzer apparatus according to claim 7 wherein the housing portion includes a reference gas chamber at the end thereof opposite the outer tubular member, said chamber substantially enclosing said housing portion opposite end; and a reference gas inlet tube in communication with said chamber for conducting reference gas from said chamber to the electrochemical cell wherein said reference gas is then vented from said gas analyzer apparatus through said reference gas vent means.

Claim 11

The gas analyzer apparatus according to claim 7 wherein the securing means are ceramic seals sealing said tubular support means within said body portion.