Method and system for gas detection

A system for monitoring a concentration of a gas and for automatically recording and displaying gas concentration data, said system comprising:

• means for sensing the concentration of the gas and for outputting an electrical signal proportional to the concentration of the gas, the sensing means being placed in fluid communication with the gas;
• means for converting said signal output from said sensing means into a series of corresponding digital signals;
• data memory means for storing a concentrations history array, said concentrations history array having stored therein in chronological order from an oldest previously stored concentration level of the gas to a newest concentration level of the gas a plurality greater than two of previously stored levels of concentration of the gas, for storing a total exposure level, and for storing a calibration table of values, each said value in the calibration table corresponding to a predetermined response of the sensing means to being placed in fluid communication with a predetermined concentration of gas;
• digital processor means for processing said digital signals so as to electronically monitor, display and record the concentration of the gas by performing a plurality of programmed steps comprising:
• comparing the digital signals with values of the calibration table;
• deriving data from said comparison step representing a derived gas level that corresponds to the predetermined response of the sensing means to being placed in fluid communication with the corresponding predetermined concentration of gas;
• electronically storing the derived gas level in the concentrations history array, said concentrations history array having stored therein a plurality greater than two of previously stored levels of concentration of the gas, each of said previously stored levels of concentration of the gas being stored therein in chronological order from an oldest previously stored concentration level of the gas to at least two chronologically more recent concentration levels of the gas, said derived gas level being stored in said concentrations history array so as to replace the oldest previously stored concentration level of gas in the data memory means;
• summing said plurality greater than two of previously stored levels of concentration of the gas to arrive at the total exposure level;
• electronically storing the total exposure level in the data memory means;
• automatically displaying the derived gas level in a visually perceptible manner to a system user;
• and
• automatically displaying in a visually perceptible manner to the system user a diagnostic when the total exposure level in the data memory means exceeds a predetermined alarm level;
• program memory means for storing machine-readable instructions utilized by said digital processor means to carry out said plurality of programmed steps;
• and
• display means, electrically connected to said digital processor means, for outputting a visual display of the derived gas level, and for outputting a visual display of the diagnostic when the total exposure level exceeds the predetermined alarm level.

A system for monitoring a concentration of a gas and for automatically recording and displaying concentration data, comprising:

• means for sensing the concentration of the gas and for outputting an electrical signal proportional to the concentration of the gas, the sensing means being placed in fluid communication with the gas;
• means for converting said signal output from said sensing means into a series of corresponding digital signals;
• digital processor means for processing said digital signals so as to electronically monitor, display and record the concentration of the gas by performing a plurality of programmed steps comprising:
• deriving data from said digital signals which represents a level of concentration of the gas;
• electronically storing the level of concentration of the gas as a newest concentration level of the gas in a concentrations history array, said concentrations history array having stored therein in chronological order from an oldest previously stored concentration level of the gas to the newest concentration level of the gas a plurality greater than two of previously stored levels of concentration of the gas;
• subtracting the oldest previously stored concentration level of the gas from a sum of the plurality of previously stored concentration levels of the gas to arrive at an intermediate sum;
• adding the level of the concentration of the gas to the intermediate sum to arrive at a total exposure level;
• electronically storing the total exposure level for later retrieval and output;
• automatically displaying the level of concentration of the gas in a visually perceptible manner to a system user;
• and
• automatically displaying in a visually perceptible manner to the system user a diagnostic when the total exposure level exceeds a predetermined alarm level;
• data memory means for storing the total exposure level and the concentrations history array;
• program memory means for storing machine-readable instructions utilized by said digital processor means to carry out said plurality of programmed steps;
• and
• display means, electrically connected to said digital processor means, for outputting a visual display of the level of concentration of the gas and a visual display of the diagnostic when the total exposure level exceeds the predetermined alarm level.

A system for monitoring a concentration of a gas and for automatically recording and displaying gas concentration data, said system comprising:

• means for sensing the concentration of the gas, said sensing means comprising:
• a catalyzing element;
• a heating material separate from and in thermal communication with said catalyzing element;
• a means for cyclically heating said heating material, said cyclical heating means heating said catalyzing element by application of a first predetermined electrical voltage for a first predetermined time to said heating material so as to cause the catalyzing element to be heated above a catalyzing temperature range of the gas, and wherein the cyclical heating means heats said heating material by application of a second predetermined electrical voltage for a second predetermined time so as to cause the catalyzing element to be heated within the catalyzing temperature range of the gas;
• a means for continuous sensing of the catalyzing element, wherein said continuous sensing means senses said catalyzing element when the catalyzing element is heated both above and within the catalyzing temperature range of the gas, and for continuously outputting an electrical signal proportional to the concentration of the gas in fluid communication with the catalyzing element when the catalyzing element is heated to a temperature within the catalyzing temperature range of the gas;
• means for converting said electrical signal output from said means for continuous sensing of the catalyzing element into a series of corresponding digital signals;
• digital processor means for processing said digital signals so as to electronically monitor, display and record the concentration of the gas in fluid communication with the catalyzing element by performing a plurality of programmed steps comprising:
• deriving data from said digital signals which represents a level of concentration of the gas;
• and
• automatically displaying the level of concentration of the gas in a visually perceptible manner to a system user;
• program memory means for storing machine-readable instructions utilized by said digital processor means to carry out said plurality of programmed steps;
• and
• display means, electrically connected to said digital processor means, for outputting a visual display of the level of the concentration of the gas.