US3907657A — Gas analysis apparatus

Claim 1

Independent Claim 228 words

A GAS ANALYSIS APPARATUS FOR MEASURING THE CONCENTRATION OF A GASEOUS COMPONENT IN A FIRST SPACE COMPRISING, A CHAMBER HAVING WALL MEANS THAT DEFINE A MEASURING SPACE WHICH RECEIVES A MEASURING GAS SAMPLE FROM THE FIRST SPACE VIA CONNECTING MEANS THAT PRESENT A HIGH GAS FLOW TRANSFER RESISTANCE, SAID WALL MEANS INCLUDING A PARTITION WHICH IS PART OF A WALL SECTION OF THE MEASURING SPACE AND COMPRISING AT LEAST ONE SOLID SUBSTANCE EXHIBITING IONIC CONDUCTION, FIRST AND SECOND ELECTRODE LAYERS AFFIXED TO OPPOSITE SIDES OF SAID PARTION FOR RECEIVING AN ELECTRIC CURRENT, SO THAT BY MEANS OF A CURRENT OF IONS IN THE PARTITION THE GASEOUS COMPONENT IS REMOVED FROM THE MEASURING SPACE, A CONTROL UNIT FOR APPLYING AN ELECTRICC CURRENT TO SAID FIRST AND SECOND ELECTRODES DURING A PUMPING TIME TP AN INCLUDING MEANS FOR INTERRUPTING THE FLOW OF CURRENT TO SAID ELECTRODES DURING A FILLING TIME IF, THE TRANSFER RESISTANCE OF SAID CONNECTING MEANS BEING CHOSEN SO THAT, OWING TO DIFFUSION, THE RATIO OF THE CONCENTRATIONS OF THE GASEOUS COMPONENT IN THE SAID TWO SPACES IS BROUGHT TO A SUBSTANTIALLY UNITY VALUE DURING THE FILLING TIME, AND THE CONTROL UNIT FOR THE ELECTRIC CURRENT FURTHER COMPRISES MWEANS FOR APPLYING AN ELECTRIC CURRENT TO SAID ELECTRODES AFTER THE FILLING TIME AND DURING A PUMPING TIME TP SUCH THAT THE RATIO OF THE GAS CONCENTRATIONS BECOMES SUBSTANTIALLY ZERO,

Claim 2

Dependent Claim 228 words

A GAS ANALYSIS APPARATUS FOR MEASURING THE CONCENTRATION OF A GASEOUS COMPONENT IN A FIRST SPACE COMPRISING, A CHAMBER HAVING WALL MEANS THAT DEFINE A MEASURING SPACE WHICH RECEIVES A MEASURING GAS SAMPLE FROM THE FIRST SPACE VIA CONNECTING MEANS THAT PRESENT A HIGH GAS FLOW TRANSFER RESISTANCE, SAID WALL MEANS INCLUDING A PARTITION WHICH IS PART OF A WALL SECTION OF THE MEASURING SPACE AND COMPRISING AT LEAST ONE SOLID SUBSTANCE EXHIBITING IONIC CONDUCTION, FIRST AND SECOND ELECTRODE LAYERS AFFIXED TO OPPOSITE SIDES OF SAID PARTION FOR RECEIVING AN ELECTRIC CURRENT, SO THAT BY MEANS OF A CURRENT OF IONS IN THE PARTITION THE GASEOUS COMPONENT IS REMOVED FROM THE MEASURING SPACE, A CONTROL UNIT FOR APPLYING AN ELECTRICC CURRENT TO SAID FIRST AND SECOND ELECTRODES DURING A PUMPING TIME TP AN INCLUDING MEANS FOR INTERRUPTING THE FLOW OF CURRENT TO SAID ELECTRODES DURING A FILLING TIME IF, THE TRANSFER RESISTANCE OF SAID CONNECTING MEANS BEING CHOSEN SO THAT, OWING TO DIFFUSION, THE RATIO OF THE CONCENTRATIONS OF THE GASEOUS COMPONENT IN THE SAID TWO SPACES IS BROUGHT TO A SUBSTANTIALLY UNITY VALUE DURING THE FILLING TIME, AND THE CONTROL UNIT FOR THE ELECTRIC CURRENT FURTHER COMPRISES MWEANS FOR APPLYING AN ELECTRIC CURRENT TO SAID ELECTRODES AFTER THE FILLING TIME AND DURING A PUMPING TIME TP SUCH THAT THE RATIO OF THE GAS CONCENTRATIONS BECOMES SUBSTANTIALLY ZERO,

Claim 3

Dependent Claim 26 words

A gas analysis apparatus as claimed in claim 1, characterized in that the connecting means comprises a porous wall section of the measuring space wall means.

Claim 4

Dependent Claim 21 words

A gas analysis apparatus as claimed in claim 1, characterized in that the connecting means comprises at least one capillary element.

Claim 5

Dependent Claim 19 words

A gas analysis apparatus as claimed in claim 1, characterized in that the connecting means comprises a semipermeable membrane.

Claim 6

Dependent Claim 42 words

A gas analysis apparatus as claimed in claim 4, characterized in that the semipermeable membrane is made of the same solid substance of which the said partition is made, and that the electrode layers on opposite sides of the partition are interconnected.

Claim 7

Dependent Claim 82 words

A gas analysis apparatus as claimed in claim 1 wherein the control unit includes a charge measuring apparatus for measuring the charge supplied by the control unit during the pumping time interval tp and further includes a detection circuit, which is connected to an electrode layer, both at the one side and at the other side of the partition, and which for a specific voltage variation between these electrode layers supplies a stop signal which indicates the end of the charge measurement.

Claim 8

Dependent Claim 53 words

A gas analysis apparatus as claimed in claim 6 further comprising a temperature measuring circuits which measures the temperature T in degrees Kelvin in the measuring space and corrects the charge measurement of the charge measuring apparatus at least in the operating temperature range of the measuring space by a factor of 1/T.

Claim 9

Dependent Claim 50 words

A gas analysis apparatus as claimed in claim 6 further comprising means for varying the measuring space volume as a fUnction of temperature so that the volume of the measuring space, at least in the operating temperature range, is proportional to the measuring space absolute temperature T in degrees Kelvin.

Claim 10

Dependent Claim 65 words

A gas analysis apparatus as claimed in claim 6 wherein the charge measuring apparatus includes a current source circuit which supplies said electric current, and a time measuring circuit which measures the time interval tp, as a measure of the concentration of the gaseous component, from the time that the current is applied to the electrode layers until the detection circuit supplies the stop signal.

Claim 11

Dependent Claim 62 words

A gas analysis apparatus as claimed in claim 6 wherein the charge measuring apparatus includes a pulse source which supplies the electric current in the form of pulses with a known charge, and includes a counting circuit, which during the time interval tp counts the number of pulses from the pulse source as a measure of the concentration of the gaseous component.

Claim 12

Dependent Claim 37 words

A gas analysis apparatus as claimed in claim 6 wherein the detection circuit includes a differentiator which differentiates the specific voltage variation on said electrode layers and derives the stop signal from the pulse-shaped signal thus obtained.

Claim 13

Dependent Claim 66 words

A gas analysis apparatus as claimed in claim 6 wherein the control unit and the detection circuit are connected to the same electrode layers and that the detection circuit includes a compensator, which compensates for the voltage drop IR across the electrode layers during the time interval tp for a level detector, and supplies the stop signal when the specific voltage variation exceeds a reference level.

Claim 14

Dependent Claim 64 words

A gas analyser for determining the concentration of gaseous components in the exhaust gases of a combustion engine by means of a gas analysis apparatus as claimed in claim 1 wherein the first space forms part of the exhaust system of the combustion engine and at least the wall section with the partition of the measuring space is in contact with the exhaust gases.

Claim 15

Dependent Claim 208 words

A gas analysis apparatus for measuring the concentration of a gas component in a gas mixture located within a first space comprising, a chamber having wall sections that define a measuring space for receiving a gas sample from the first space during a first time interval, means for coupling the first space to the measuring space that includes a member having a high gas flow transfer resistance chosen so that the gas diffusion rate from the first space to the measuring space allows the concentration ratio of the said gas component in said two spaces to achieve a substantially unity value within the first time interval, said chamber including a wall section with a partition comprising a solid substance capable of ionic conduction and with first and second electrode means affixed to opposite sides of the partition, control means coupled to said first and second electrode means for applying an electric current thereto during a second time interval that is substantially shorter than said first time interval whereby the gas component is substantially completely removed from the measuring space via ionic conduction in said partition, said control means including means for interrupting the flow of current to said first and second electrode means during said first time interval.

Claim 16

Dependent Claim 208 words

A gas analysis apparatus for measuring the concentration of a gas component in a gas mixture located within a first space comprising, a chamber having wall sections that define a measuring space for receiving a gas sample from the first space during a first time interval, means for coupling the first space to the measuring space that includes a member having a high gas flow transfer resistance chosen so that the gas diffusion rate from the first space to the measuring space allows the concentration ratio of the said gas component in said two spaces to achieve a substantially unity value within the first time interval, said chamber including a wall section with a partition comprising a solid substance capable of ionic conduction and with first and second electrode means affixed to opposite sides of the partition, control means coupled to said first and second electrode means for applying an electric current thereto during a second time interval that is substantially shorter than said first time interval whereby the gas component is substantially completely removed from the measuring space via ionic conduction in said partition, said control means including means for interrupting the flow of current to said first and second electrode means during said first time interval.

Claim 17

Dependent Claim 103 words

A gas analysis apparatus as claimed in claim 14 wherein said control means includes a source of electric current for said first and second electrode means and detection means connected to said first and second electrode means and responsive to an electric signal developed thereat for causing the control means to interrupt the flow of electric current from said current source to said first and second electrode means when the gas component is substantially completely removed from the measuring space thereby terminating the second time interval, and said control means includes means for measuring the electric charge transferred during the second time interval.

Claim 18

Dependent Claim 54 words

A gas Analysis apparatus as claimed in claim 15 further comprising means for deriving a control signal determined by the temperature of the measuring space, and means for applying said control signal to the control means for adjusting the electric charge measuring means such that the charge measurement is inversely proportional to said temperature.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-09-22	1979-03-24	1979-09-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-09-22	1983-03-24	1983-09-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-09-22	1987-03-24	1987-09-23	$7700.00	Window Closed / Lapsed

Gas analysis apparatus

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