US 5,305,231 AGranted

Multiple K factor, selectable gas detector

AssigneeBacharach, Inc.

InventorsMark J. Coppler, Robert L. Novack, John E. Tozier, Peter M. Noble

Life of this patent

Estimating the term…

Loading patent…

Abstract

A gas detector apparatus for determining the concentration of a selected one of a plurality of predetermined gases includes a gas sensor which generates a gas output signal related to the concentration of the selected predetermined gas in the gas sample. A K factor storage associated with the gas sensor stores at least one K factor, unique to and generated by using the gas sensor, for each of the plurality of predetermined gases. A processor, in response to a selected gas control signal, selects the K factor or factors from the K factor storage for the selected gas and, in accordance with a predetermined process stored therein, calculates a concentration signal representing the concentration of the selected gas in the gas sample.

Claims51

Dependent claims

Gas detecting apparatus for determining the concentration, in a gas sample, of a selected one of a plurality of predetermined gases, said apparatus comprising:

sampling means for obtaining said gas sample;
a single gas sensor connected to said sampling means for generating a gas output signal related to the concentration of said selected predetermined gas in said gas sample;
drive means for supplying controlled electrical power to said gas sensor;
K factor storage means associated with said gas sensor for storing at least one K factor, unique to and generated by using said gas sensor, for each of said plurality of predetermined gases;
gas selector means for generating a selected gas signal representing the particular selected gas to be detected;
a processor means for selecting, in response to the selected gas signal and gas output signal, the K factor or factors from said K factor storage means for the selected gas and for calculating, in accordance with a predetermined process stored in said processor means, a concentration signal representing the concentration of the selected gas in said gas sample;
and
display means responsive to said concentration signal for displaying the concentration of said gas to be detected in said gas sample.

5 more elements

Gas detecting apparatus for determining the concentration, in a gas sample, of a selected one of a plurality of predetermined combustible gases, said apparatus comprising:

sampling means for obtaining said gas sample;
a single combustible gas sensor connected to said sampling means for generating a combustible gas output signal related to the concentration of said selected predetermined combustible gas in said sample;
drive means for supplying controlled electrical power to said combustible gas sensor;
K factor storage means associated with said combustible gas sensor for storing at least one K factor, unique to and generated by using said combustible gas sensor, for each of said plurality of predetermined combustible gases;
gas selector means for generating a selected gas signal representing the particular selected combustible gas to be detected;
a processor means for selecting, in response to the selected gas signal and combustible gas output signal, the K factor or factors from said K factor storage means for the selected combustible gas in said gas sample;
and
display means responsive to said concentration signal for displaying the concentration of said combustible gas to be detected in said gas sample.

5 more elements

Gas detecting apparatus for determining the concentration, in a gas sample, of a selected one of a plurality of predetermined combustible gases, said apparatus comprising:

sampling means for obtaining said gas sample;
a single combustible gas sensor connected to said sampling means for generating a combustible gas output signal related to the concentration of said selected predetermined combustible gas in said gas sample;
drive means for supplying controlled electrical power to said combustible gas sensor;
an oxygen sensor connected to said sampling means for generating an oxygen output signal proportional to the concentration of oxygen in said gas sample;
K factor storage means associated with said combustible gas sensor for storing at least one K factor, unique to and generated by using said combustible gas sensor, for each of said plurality of predetermined combustible gases;
gas selector means for generating a selected gas signal representing the particular selected combustible gas to be detected;
a mode selector means for generating a mode signal representing the mode of operation of said apparatus, with said mode selector means selectable between at least an oxygen detection mode and a combustible gas detection mode;
a processor means for (i) in response to the mode signal, selected gas signal, combustible gas output signal and oxygen output signal, and using predetermined processes stored in said processor means, calculating a first concentration signal representing the concentration of oxygen detected in said gas sample, or (ii) selecting the K factor or factors from said K factor storage means for the selected combustible gas and calculating a second concentration signal representing the concentration of the selected combustible gas in said gas sample;
and
display means responsive to said first and second concentration signals for displaying, as determined by the mode signal, either the concentration of oxygen to be detected in said gas sample or the concentration of combustible gas to be detected in said gas sample.

7 more elements

Gas detecting apparatus for determining the concentration, in a gas sample, of a selected one of a plurality of predetermine combustible gases, said apparatus comprising:

sampling means for obtaining said gas sample;
a single combustible gas sensor connected to said sampling means for generating a combustible gas output signal related to the concentration of said selected predetermined combustible gas in said gas sample;
drive means for supplying controlled electrical power to said combustible gas sensor;
an oxygen sensor connected to said sampling means for generating an oxygen output signal proportional to the concentration of oxygen in said gas sample;
K factor storage means associated with said combustible gas sensor for storing at least one K factor, unique to and generated by using said combustible gas sensor, for each of said plurality of predetermined combustible gases;
gas selector means for generating a selected gas signal representing the particular selected combustible gas to be detected;
a mode selector means for generating a mode signal representing the mode of operation of said apparatus, with said mode selector means selectable between at least an oxygen detection mode and a combustible gas detection mode;
a processor means for (i) in response to the mode signal, selected gas signal, combustible gas output signal and oxygen output signal, and using predetermined processes stored in said processor means, calculating a first concentration signal representing the concentration of oxygen detected in said gas sample, or (ii) selecting the K factor or factors from said K factor storage means for the selected combustible gas and calculating a second concentration signal representing the concentration of the selected combustible gas in said gas sample;
and
display means responsive to said first and second concentration signals for displaying, as determined by the mode signal, either the concentration of oxygen to be detected in said gas sample or the concentration of combustible gas to be detected in said gas sample,
wherein the K factors stored in said K factor storage means are generated in advance for a particular combustible gas sensor in accordance with the following steps:
a. applying electrical power to said combustible gas sensor;
b. measuring the combustible gas output signal when clean air is applied to said combustible gas sensor;
c. applying a first of said predetermined combustible gases in a known concentration to said combustible gas sensor and measuring the combustible gas output signal generated thereby;
d. calculating the K factor of said first combustible gas based upon the combustible gas output signals generated in steps (b) and (c) above and the known concentration of said first combustible gas;
and
e. repeating steps (b) through (d) for each of the remaining of said predetermined combustible gases.

14 more elements

Dependencies are inferred from the claim text.