Detector for fumes and combustion gases

Claim 2

An ionization detector for detecting fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned within a housing; a radioactive means arranged for causing the ionization of particles within said chambers; means for providing a flow path for atmospheric fumes, vapors or aerosols from an environment within which the detector is located to said sensing chamber; means for providing an electrical output signal from said chambers indicative of the presence of a fume, vapor or aerosol in said sensing chamber; and circuit storage means coupled to said latter means and responsive to said electrical signal for providing an indication of the elapsed time between the initial occurrences of the fumes, vapors or aerosols in the sensing chamber and a subsequent instant of time.

Claim 3

An ionization detector for detecting fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned within a housing: a radioactive means arranged for causing the ionization of particles within said chambers; means for providing a flow path for atmospheric fumes, vapors or aerosols from an environment within which the detector is located to said sensing chamber; means for providing an electrical output signal from said chambers indicative of the presence of a fume, vapor or aerosol in said sensing chamber; and electrical circuit storage means and circuit means responsive to said output signal for causing said electrical circuit storage means to continuously accumulate a sum after an initial occurrence of said output signal and providing an indication of the elapsed time between the initial occurrences of the fumes, vapors or aerosols in the sensing chamber and a subsequent instant of time.

Claim 4

An ionization detector for detecting fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned within a housing: a radioactive means arranged for causing the ionization of particles within said chambers; means for providing a flow path for atmospheric fumes, vapors or aerosols from an environment within which the detector is located to said sensing chamber; means for providing an electrical output signal from said chambers indicative of the presence of a fume, vapor or aerosol in said sensing chamber; and electrical circuit storage means and circuit means responsive to said output signal for causing said electrical circuit storage means to continuously accumulate a sum after an initial occurrence of said output signal and providing an indication of the elapsed time between the initial occurrences of the fumes, vapors or aerosols in the sensing chamber and a subsequent instant of time.

Claim 5

The detection means of claim 2 wherein said electrical storage means comprises a counter.

Claim 6

The detection means of claim 3 wherein said circuit means for causing said storage means to accumulate a sum comprises a circuit arrangement for generating periodically recurring impulses.

Claim 7

The detection means of claim 4 wherein said circuit means for generating periodically recurring pulses comprises an operational amplifier having a feedback network coupled thereto for causing said amplifier to function as an integrating means.

Claim 8

An ionization detector for providing an indication of the presence of fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned in a housing; each of said ionization chambers having an anode electrode and a cathode electrode; said ionization chambers coupled electrically in series and having a cathode electrode of one of said chambers and an anode electrode of the other of said chambers which is common to each of said chambers; a switching circuit means; electrical storage means coupled to said switching circuit means and de-energized by said switching means when said switching circuit means exists in a first of two states and energized when said switching circuit means exists in a second of two states; circuit means coupled between said switching circuit means and said storage means for providing a continuous entry to said storage means when said switching means exists in said second state; and circuit means coupled between said common electrode and said switching circuit means for causing said switching circuit means to exist in said first state during the absence of vapors, fumes or aerosols within said sensing chamber and for causing said switching circuit means to switch to said second state when vapors, fumes or aerosols exist in said sensing chamber.

Claim 9

An ionization detector for providing an indication of the presence of fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned in a housing; each of said ionization chambers having an anode electrode and a cathode electrode; said ionization chambers coupled electrically in series and having a cathode electrode of one of said chambers and an anode electrode of the other of said chambers which is common to each of said chambers; a switching circuit means; electrical storage means coupled to said switching circuit means and de-energized by said switching means when said switching circuit means exists in a first of two states and energized when said switching circuit means exists in a second of two states; circuit means coupled between said switching circuit means and said storage means for providing a continuous entry to said storage means when said switching means exists in said second state; and circuit means coupled between said common electrode and said switching circuit means for causing said switching circuit means to exist in said first state during the absence of vapors, fumes or aerosols within said sensing chamber and for causing said switching circuit means to switch to said second state when vapors, fumes or aerosols exist in said sensing chamber.

Claim 10

The detection means of claim 6 wherein said indicating means comprises an electrically energized indicator which provides an indication which is perceptible by the human senses.

Claim 11

The detection means of claim 7 wherein said indicating means comprises a visual indicator mounted on said housing.

Claim 12

The detection means of claim 6 wherein said indicating means comprises an electrical storage means and circuit means for providing a continuous entry to said storage means when said switching means exists in said second state.

Claim 13

An ionization detector for sensing vapors, fumes and aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned within the housing; each of said ionization chambers having a cathode and an anode electrode; radioactive means arranged for causing ionization of particles within said chambers; means for providing access to said sensing chamber for environmental constituents such as fumes, vapors or aerosols which are to be detected. said reference chamber adapted to inhibit the entry of environmental constituents into the reference chamber and to maintain a predetermined enviRonment established therein; said reference chamber containing a predetermined level of environmental pollutants corresponding to the level of pollutants existing in the environment within which as detector is to be located; and means coupled to said chambers for providing an indication of the existence of fumes, vapors or aerosols in said sensing chamber.

Claim 14

An ionization detector for sensing vapors, fumes and aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned within the housing; each of said ionization chambers having a cathode and an anode electrode; radioactive means arranged for causing ionization of particles within said chambers; means for providing access to said sensing chamber for environmental constituents such as fumes, vapors or aerosols which are to be detected. said reference chamber adapted to inhibit the entry of environmental constituents into the reference chamber and to maintain a predetermined enviRonment established therein; said reference chamber containing a predetermined level of environmental pollutants corresponding to the level of pollutants existing in the environment within which as detector is to be located; and means coupled to said chambers for providing an indication of the existence of fumes, vapors or aerosols in said sensing chamber.

Claim 15

The detection means of claim 10 wherein said reference chamber contains carbon monoxide at a concentration of 3 mg/m3.

Claim 16

An ionization detector for providing an indication of the presence of fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned in a housing; each of said ionization chambers having an anode electrode and a cathode electrode; said ionization chambers coupled electrically in series and having a cathode electrode of one of said chambers and an anode electrode of the other of said chambers which is common to each of said chambers; a switching circuit means; electrical storage means coupled to said switching circuit means and de-energized by said switching means when said switching circuit means exists in a first of two states and energized when said switching circuit means exists in a second of two states; circuit means coupled between said common electrode and said switching circuit means for causing said switching circuit means to exist in said first state during the absence of vapors, fumes or aerosols within said sensing chamber and for causing said switching circuit means to switch to said second state when vapors, fumes or aerosols exist in said sensing chamber; and, circuit means for causing said switching means to alternatively switch to said second state upon the occurrence of a fault in the operation of said ionization chambers.

Claim 17

An ionization detector for providing an indication of the presence of fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned in a housing; each of said ionization chambers having an anode electrode and a cathode electrode; said ionization chambers coupled electrically in series and having a cathode electrode of one of said chambers and an anode electrode of the other of said chambers which is common to each of said chambers; a switching circuit means; electrical storage means coupled to said switching circuit means and de-energized by said switching means when said switching circuit means exists in a first of two states and energized when said switching circuit means exists in a second of two states; circuit means coupled between said common electrode and said switching circuit means for causing said switching circuit means to exist in said first state during the absence of vapors, fumes or aerosols within said sensing chamber and for causing said switching circuit means to switch to said second state when vapors, fumes or aerosols exist in said sensing chamber; and, circuit means for causing said switching means to alternatively switch to said second state upon the occurrence of a fault in the operation of said ionization chambers.

Claim 18

An ionization detector for providing an indication of the presence of fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned in a housing; each of said ionization chambers having an anode electrode and a cathode electrode; said ionization chamber coupled electrically in series and having a cathode electrode of one of said chambers and an anode electrode of the other of said chambers which is common to each of said chambers; a first switching circuit means including a thyristor having an input trigger electrode; indicating means coupled to said switching circuit means and de-energized by said switching circuit means when said switching circuit means exists in a first of two states and energized when said switching circuit means exists in a second of two states; circuit means coupled between said common electrode and said switching circuit means for causing said switching circuit means to exist in said first state during the absence of vapors, fumes or aerosols within said sensing chamber and for causing said switching circuit means to switch to said second state when vapors, fumes or aersols exist in said sensing chamber, said circuit means comprising a field effect transistor amplifier circuit arrangement having an impedance coupled in an electrode circuit of the field effect transistor, and a voltage sensitive switching means coupled between said impedance and said input trigger electrode of said thyristor; and, amplifier circuit means having an input thereto coupled from the impedance of said field effect transistor circuit arrangement and switching means coupled between said amplifier and said input trigger electrode of said thyristor, said switching means operative to couple said amplifier to said thyristor input trigger electrode upon the occurrence of a fault in said sensing ionization chamber.

Claim 19

An ionization detector for providing an indication of the presence of fumes, vapors or aerosols comprising: a reference ionization chamber and a sensing ionization chamber positioned in a housing; each of said ionization chambers having an anode electrode and a cathode electrode; said ionization chamber coupled electrically in series and having a cathode electrode of one of said chambers and an anode electrode of the other of said chambers which is common to each of said chambers; a first switching circuit means including a thyristor having an input trigger electrode; indicating means coupled to said switching circuit means and de-energized by said switching circuit means when said switching circuit means exists in a first of two states and energized when said switching circuit means exists in a second of two states; circuit means coupled between said common electrode and said switching circuit means for causing said switching circuit means to exist in said first state during the absence of vapors, fumes or aerosols within said sensing chamber and for causing said switching circuit means to switch to said second state when vapors, fumes or aersols exist in said sensing chamber, said circuit means comprising a field effect transistor amplifier circuit arrangement having an impedance coupled in an electrode circuit of the field effect transistor, and a voltage sensitive switching means coupled between said impedance and said input trigger electrode of said thyristor; and, amplifier circuit means having an input thereto coupled from the impedance of said field effect transistor circuit arrangement and switching means coupled between said amplifier and said input trigger electrode of said thyristor, said switching means operative to couple said amplifier to said thyristor input trigger electrode upon the occurrence of a fault in said sensing ionization chamber.