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US 6,687,005 B2Granted
Combustible gas detector and method for operating same
AssigneeKorea Industrial Safety Corporation
InventorKyu-Jung Kim
Life of this patent
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Abstract
A method and apparatus for protecting workers from casualty due to a combustible gas. A portable combustible gas detector is disclosed which is particularly suitable for portable use. The detector generally comprises a circuit, housed in the same chamber as the sensor, for controlling the operation of the gas detector; and operation software for operating the detector through the circuit. The circuit of the detector is encased in armor to protect the circuit from electromagnetic wave disturbance. The detector is particularly suitable for measurement of a combustible gas with a low concentration. Advantageously, the present invention enables a worker to conveniently carry a small and lightweight combustible gas detector into a hazardous worksite to improve the safety of each worker carrying the device.
Claims26
A portable combustible gas detector apparatus for detecting a combustible gas, comprising:
- a housing defining an inner chamber between a first end and a second end, said second end having an access opening to said chamber;
- a sensor device disposed within said chamber in communication with said access opening and being operable for sensing and measuring gas levels, and for providing sensor signals in response to said sensed gas levels;
- a circuit disposed within said chamber and being operable for processing input signals associated with sensed gas levels and generating output signals, said circuit comprising:
- a sensor driving circuit operationally coupled to said sensor, said sensor driving circuit for maintaining said sensor device in an operational state, and for converting said sensor signals into analog voltage sensor signals;
- a signal conditioning circuit operationally coupled to said sensor driving circuit, said signal conditioning circuit for amplifying and converting said analog voltage sensor signals;
- an analog to digital (A/D) converter for converting said analog sensor signals into digital sensor signals;
- a central processing unit (CPU) for processing the digital sensor signals into data having a data format that can be processed by a central processor unit (CPU);
- calibration means for establishing a sensor zero point, said calibration means requiring manual actuation of a power switch for a predetermined minimum period of time;
- operational software for controlling a plurality of operations of the portable gas detector through said circuit;
- and
- power supply means for supplying a direct current to said circuit.
8 more elements
A method for operating a combustible gas detector, the method comprising:
- driving the combustible gas detector;
- initializing the combustible gas detector;
- performing a self-diagnostic procedure;
- activating a measurement mode;
- determining whether a key-in is activated;
- activating a sub-menu in the event said key-in is activated;
- and
- otherwise activating a power saving mode in the event said key-in is not activated.
5 more elements
A portable combustible gas detector for protecting workers from casualty originating from inadvertent exposure to a combustible gas, the detector comprising:
- a sensor device;
- a control circuit for controlling a plurality of operational states of the gas detector, said control circuit further comprising:
- a sensor driving circuit operationally coupled to said sensor device, said sensor driving circuit for maintaining said sensor device in an operational state, and for converting said sensor signals into analog voltage sensor signals;
- a signal conditioning circuit operationally coupled to said sensor driving circuit, said signal conditioning circuit for amplifying and converting said analog voltage sensor signals;
- an analog to digital (A/D) converter for converting said analog sensor signals into digital sensor signals;
- a central processing unit (CPU) for processing the digital sensor signals into data having a data format that can be processed by a central processor unit (CPU);
- an electrically erasable programmable memory (EEPROM) for storing data processed by said CPU and for storing operation software, said operation software for operating the gas detector via said control circuit
- an armor case for protecting said control circuit from electromagnetic wave disturbance;
- a clip installed on one side of said armor case for attaching said detector to a worker's uniform;
- a power switch for delivering/removing power from the gas detector;
- a battery for supplying a direct current power for operating said control circuit;
- an LED display for displaying operational states of the gas detector;
- an audible alarm including a plurality of alarm classes, wherein each of said plurality of alarm classes is indicative of whether the operational state of said gas detector is in a normal operational condition or in a malfunction condition;
- and
- self-diagnostic means for diagnosing any low voltage and any malfunction of the sensor device and/or circuit.
12 more elements
A method for operating a combustible gas detector comprising the steps of:
- turning on the gas detector;
- initializing an external interrupt and a timer of the gas detector;
- and
- reading one or more parametric values;
- conducting a self-diagnostic procedure of the gas detector upon completion of the initialization step, said self-diagnostic procedure including the steps of:
- depressing a test switch for a prescribed time;
- checking operational conditions of a sensor, a battery and an internal circuit to determine if said gas detector is in one of a normal or malfunction condition;
- activating a green LED lamp to an ON state and sounding an audible alarm twice in the event said gas detector is determined to be in a normal condition at said checking step;
- and
- activating a red LED lamp to an ON state and sounding an audible alarm once in the event said gas detector is determined to be in a malfunction condition at said checking step;
- activating a measurement mode upon completion of the conducting step, comprising the steps of:
- activating an external stable voltage;
- performing an A/D conversion;
- calibrating a gas value;
- calculating a gas value;
- checking the alarm;
- and
- checking a time-out;
- determining whether a key-in is activated after said measurement mode has been activated;
- activating a sub-menu in the event said key-in is activated, comprising the steps of:
- performing a zero point calibration and a span calibration simultaneously;
- and
- conducting a function to prevent a wrong operation;
- otherwise activating a power saving mode in the event said key-in is not activated.
21 more elements
Dependencies are inferred from the claim text.