Portable combustible gas detector

• US 6,987,459 B2
• Filed: 01/24/2003
• Issued: 01/17/2006
• Est. Priority Date: 01/24/2003
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Tice, Lee D.
• Primary Examiner(s): Wu, Daniel
• Assistant Examiner(s): Walk, Samuel J.
• Application Number:
  US10/351,271
• Publication Number:
  US 20040145485A1
• Time in Patent Office: 1,089 Days
• Field of Search: 340/632, 340/693.6, 73/310.5, 73/233.1, 73/351.5, 422/83, 422/94, 422/280
• US Class Current: 340/632
• CPC Class Codes: G01N 33/0009 General constructional details of gas analysers, e.g. portable test equipment devices for withdrawing samples in the gaseous state G01N1/22
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array
• CPC Class Codes: G01N 33/0047 Organic compounds
• CPC Class Codes: G01N 33/005 H2
• CPC Class Codes: G08B 21/16 Combustible gas alarms

Abstract

A portable detector of combustible or explosive gases incorporates a polymeric-type sensor or sensor array coupled to a programmed processor which carries out an evaluation of one or more signals from the sensor or array to evaluate the presence of combustible or explosive vapors. Non-polymeric sensors such as temperature sensors, humidity sensors and/or pressure sensors can also be incorporated and their outputs evaluated to compensate the outputs of the sensor or array of sensors. The detector can be housed in a sealed enclosure and energized by a battery.

Claims

1. A portable combustible gas detector for sensing at least one combustible gas, the detector comprising:

an array of polymer-type sensors, the sensors respond primarily to a predetermined combustible gas and generate at least one of, different signals for the same concentration of gas, or, similar signals for the same concentration of gas;

a filter positioned between the at least one polymer sensor and the environment;

a processor with an input to receive the signals from the sensors, the processor makes a determination of gas concentration;

the processor includes at least one output port coupled to an indicating device to provide an indication of the concentration of the predetermined combustible gas wherein a solid metal condenser is carried between the filter and polymer-type sensors to remove water vapors that pass through the filter;

an enclosure which contains the array, the filter the processor, the indicating device and the condenser where the enclosure provides an opening for an inflow of ambient atmosphere; and

a region defined in the enclosure for at least selected components where the region is sealed from the condenser.

2. A detector as in claim 1 wherein the condenser comprises metal that has a relatively high mass and thermal conductivity.

3. A portable combustible gas detector for sensing at least one combustible gas, the detector comprising:

an enclosure;

a plurality of different polymer-type gas sensors, the sensors primarily respond to a single, predetermined combustible gas, with sensors of the plurality generating different signals for the same concentration of the predetermined gas;

at least one non-polymer sensor that senses a condition different than gas and generates a signal indicative thereof;

a filter positioned between the polymer-type sensors and the environment;

a processor with an input to receive the signals from all of the sensors, the processor makes a determination of concentration of the predetermined gas;

the processor includes at least one output port coupled to an indicating circuit to provide an indication of the concentration of the combustible gas.

4. A detector as in claim 3 wherein the gas is selected from a class of gases having an optical absorption peak in a wavelength between 3 microns and 4 microns.

5. A detector as in claim 4 wherein the at least one non-polymer sensor includes a temperature sensor.

6. A detector as in claim 5 wherein the temperature sensor includes a thermistor.

7. A detector as in claim 4 wherein the at least one non-polymer sensor includes a humidity sensor.

8. A detector as in claim 4 wherein the at least one non-polymer sensor includes a pressure sensor.

9. A portable combustible gas detector for sensing at least one combustible gas, the detector comprising:

an enclosure;

a plurality of different polymer-type gas sensors, the sensors primarily respond to a single, predetermined combustible gas with sensors of the plurality generating similar signals for the same concentration of the combustible gas;

at least one non-polymer sensor that senses a condition different than gas and generates at least a second signal indicative thereof;

a filter positioned between the at least one polymer sensor and the environment;

a processor with an input to receive the signals from all of the sensors, the processor makes a determination concentration of the combustible gas;

the processor includes at least one output port coupled to an indicating circuit to provide an indication of the concentration of the predetermined combustible gas.

10. A portable combustible gas detector comprising:

an enclosure;

a first plurality of polymeric sensors, the sensors primarily respond to a first combustible gas;

a second plurality of polymeric sensors, the sensors of the second plurality primarily respond to a second, different combustible gas;

a filter positioned between the polymeric sensors and an external environment;

a processor coupled to at least the sensors of the first and second pluralities;

where the processor compares sensor outputs to respective sets of multiple levels with each indicating a different concentration of the respective gas.

11. A detector as in claim 10 wherein the filter comprises a membrane-type material that passes the selected gas but resists passage of liquid water.

12. A detector as in claim 11 wherein the membrane-type material comprises, at least in part, a polymer-type material.

13. A detector as in claim 11 wherein the membrane-type material comprises a water excluding weave of material.

14. A detector as in claim 10 wherein the enclosure carries an elastic, water excluding sealing element.

15. A detector as in claim 10 which includes pre-stored polymer sensor time based performance monitoring instructions executable by the processor.

16. A detector as in claim 10 which includes pre-stored polymer sensor time based lifetime monitoring instructions executable by the processor.