Method and apparatus for engine exhaust analyzer

• US 4,348,732 A
• Filed: 01/29/1980
• Issued: 09/07/1982
• Est. Priority Date: 01/29/1980
• Status: Expired due to Term

• Current Assignee: Snap-On Tools Company LLC (Snap-On Incorporated)
• Original Assignee: Sun Electronics Corp (Snap-On Incorporated)
• Inventors: Kreft, Keith A.
• Primary Examiner(s): Atkinson, Charles E.
• Assistant Examiner(s): Chin, Gary
• Application Number:
  US06/116,406
• Time in Patent Office: 952 Days
• Field of Search: 364/571, 364/497, 364/424, 73/1 G, 73/1 R, 73/23, 73/116, 73/117.1, 60/276
• US Class Current: 702/27
• CPC Class Codes: G01N 33/0006 Calibrating gas analysers

Abstract

A processing unit for normalizing the output data of a gas analyzer in view of zero adjustment data and gain adjustment data formulated by the processing unit controlling air input and span reference simulation of a reference gas. A voltage reference generator is manually variable for calibrating the system while passing a known reference gas through the analyzer, in order to provide a scaling factor for use during output data adjustment. A hold switch is manually actuable by the operator for storing in memory the value of a gas analyzation voltage for permitting adjustment to the output data after the gas is removed from the cell of the analyzer.

Claims

1. A gas analyzation system for analyzing an unknown gas, comprising:

gas analyzing means for receiving an unknown gas to be analyzed and generating an electrical signal output representative of the analyzation of the unknown gas;

span reference means selectively actuable for simulating a reference gas, said gas analyzer means cooperating with said span reference means for generating a reference signal output representative of said reference gas in response to actuation of said span reference means;

display means responsive to display data for visually displaying an indication of gas analyzation;

data entry means for inputing a sole scaler data, said data entry means being controllable for selectively changing said sole scaler data; and

processing means including memory,

(i) for receiving said electrical signal output representative of the analyzation of the unknown gas and converting the same to gas data,

(ii) for actuating said span reference means for generating a reference signal output, for receiving said reference signal output and converting the same to reference data,

(iii) for reading said sole scalar data,

(iv) for generating display data from said gas data by adjusting said gas data in view of said reference data and said sole scalar data, and

(v) for transmitting said display data to said display device.

2. A gas analyzation system according to claim 1 wherein said electrical signal output representative of an unknown gas in an analog signal;

and wherein said processing means includes an analog-to-digital converter for converting said electrical signal output representative of the unknown gas to said gas data.

3. A gas analyzation system according to claim 1 wherein said gas analyzing means includes:

a gas analyzer for receiving a gas to be analyzed and generating an output analog signal indicative of an analyzation of the gas;

amplifier means for amplifying said output analog signal at a fixed gain; and

attenuation means selectively actuable for attenuating the output of said amplifier means, said attenuation means having a fixed attenuation.

4. A gas analyzation system according to claim 3 and further including:

gas input control means selectively actuable for passing either an unknown gas or air into said gas analyzer; and

wherein said gas analyzer receives said unknown gas passing from said gas input control means, for generating an electrical signal output representative of the analyzation of said unknown gas, and

wherein said gas analyzer receives said air passing from said gas input control means, for generating an electrical signal output representative of the analyzation of air; and

wherein said processing means actuates said gas input control means, for passing air into said gas analyzer for generating a said electrical signal output representative of the analyzation of air, said processing means for processing said electrical signal output representative of the analyzation of air for generating zero gas data, said processing means storing said zero gas data in memory, and said processing means adjusting said gas data in view of said zero gas data for generating said display data.

5. A gas analyzation system according to claim 4 wherein said processing means actuates both said gas input control means and said attenuation means, for passing air into said gas analyzer for generating a said electrical signal output representative of the analyzation of air, said processing means for processing said electrical signal output representative of the analyzation of air for generating attentuated zero gas data, said processing means storing said attenuated zero gas data in memory, and said processing means adjusting said gas data in view of said attenuated zero gas data for generating said display data.

6. A gas analyzer according to claim 1 and further including:

gas input control means selectively actuable for passing either an unknown gas or air into said gas analyzation means;

and wherein said gas analyzation means receives said unknown gas passing from said gas input control means, for generating an electrical signal output representative of the analyzation of said unknown gas, and wherein said gas analyzer receives said air passing from said gas input control means, for generating an electrical signal output representative of the analyzation of air;

and wherein said processing means actuates said gas input control means for passing air into said gas analyzation means for causing said gas analyzing means to generate an electrical signal output representative of the analyzation of air, said processing means processing said electrical signal output representative of the analyzation of air for generating zero gas data, said processing means storing said zero gas data in memory, and said processing means adjusting said gas data in view of said zero gas data for generating said display data.

7. A gas analyzation system according to claim 1 wherein said span reference means includes a mechanical flag means for providing a mechanical obstruction within said gas analyzing means for simulating said reference gas.

8. A gas analyzation system according to claim 1 wherein said data entry means includes a voltage source manually controllable for generating a variable voltage output.

9. A gas analyzation system according to claim 8 wherein said data entry means includes a resistive potentiometer manually adjustable for varying said voltage output.

10. A gas analyzation system according to claim 9 wherein said processing means retrieves said voltage output, converts said voltage output to a digital signal and stores said digital signal in memory.

11. A gas analyzation system for analyzing an unknown gas, comprising:

gas analyzing means for receiving a gas to be analyzed and generating an electrical signal output representative of the analyzation of the gas;

gas input control means selectively actuable for passing either an unknown gas or air into said gas analyzing means;

display means responsive to display data for visually displaying an indication of gas analyzation;

data entry means for inputting a sole scalar data, said data entry means being controllable for selectively changing said sole scalar data; and

processing means including memory,

(i) for actuating said gas input control means for passing air into said gas analyzing means, for causing said gas analyzing means to generate an electrical signal output representative of the analyzation of air, said processing means for processing said electrical signal output representative of the analyzation of air for generating zero adjustment data, said processing means storing said zero adjustment data in memory;

(ii) for reading said sole scalar data;

(iii) for actuating said gas input control means for passing an unknown gas into said gas analyzing means, for causing said gas analyzing means to generate an electrical signal output representative of the analyzation of an unknown gas and for converting said electrical signal output representative of the analyzation of an unknown gas to gas data, said processing means for generating display data from said gas data by adjusting said gas data in view of said zero adjustment data and said sole scalar data; and

(iv) for transmitting said display data to said display device for affecting visual display of an indication of the analyzation of the unknown gas.

12. A gas analyzation system according to claim 11 wherein said data entry means for inputting a sole scalar data includes a voltage source manually controllable for generating a variable voltage output.

13. A gas analyzation system according to claim 12 wherein said means for inputting a sole scalar data includes a resistive potentiometer manually adjustable for varying said voltage output.

14. A gas analyzation system according to claim 13 wherein said processing means retrieves said voltage output, converts said voltage output to a digital signal and stores said digital signal in memory.

15. A gas analyzation system formalizing an unknown gas, the improvement wherein the system is calibrated using a sole manually variable control, a known calibration gas and air comprising:

gas analyzing means for receiving gas and generating an electrical signal output representative of the analyzation of the gas;

input means for passing air into said gas analyzing means or for passing a known calibration gas into said gas analyzing means;

display means responsive to display data for visually displaying an indication of gas analyzation, said display means for displaying an indication of the known analyzation of said known calibration gas;

a sole manually variable control for generating variable scalar data, said control manually variable for adjusting the display of said display device for indicating said known analyzation; and

processing means including memory

(i) for processing said electrical signal output when air is passing into said gas analyzation means, for generating zero adjustment data, said processing means storing said zero adjustment data in memory;

(ii) for reading said scalar data;

(iii) for processing said signal output when a calibration gas is passing into said gas analyzing means, for generating gas data, said processing means generating display data from said gas data by adjusting said gas data in view of said zero adjustment data and said scalar data;

(iv) for transmitting said display data to said display device for affecting visual display of an indication of the analyzation of the known calibration gas; and

(v) for repeatedly reading said scalar data for repeatedly generating display data, for varying said indication in accordance with variation in said scalar data.

16. A gas analyzation system for analyzing an unknown gas, comprising:

gas analyzing means for receiving gas and generating an electrical signal output representative of the analyzation of the gas;

input means for passing gas into said gas analyzing means;

display means responsive to display data for visually displaying an indication of gas analyzation;

a hold actuator manually actuable for generating a hold signal; and

processing means including memory,

(i) for processing said electrical signal output when gas is passing into said gas analyzing means, for generating gas data, said processing means for storing said gas data in memory;

(ii) for generating display data from said gas data;

(iii) for transmitting said display data to said display device for affecting visual display of an indication of the analyzation of the gas; and

(iv) for repeatedly processing said electrical signal output for updating said gas data for affecting said visual display accordingly, ssid processing means responsive to said hold signal for discontinuing repeated processing of said electrical signal output for maintaining the value of said gas data as stored in memory.

17. A gas analyzation sysem according to claim 16 wherein said processing means generates error drift data, said processing means generating said display data from said gas data as a function of said error drift data, and wherein said processing means repeatedly updating said display data during generation of said hold signal.

18. A gas analyzation system according to claim 17 including means for providing scalar data, said means for providing scalar data being controllable for varying said scalar data;

and wherein said processing means generates display data from said gas data as a function of said error drift data and said scalar data.

19. A gas analyzation system according to claim 18 and further including a sole control knob connected to said means for providing scalar data, said control knob manually adjustable for varying said display data.