Method and system for gas detection
AssigneeGasSecure AS
InventorHåkon Sagberg
Life of this patent
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Abstract
A gas sensor is used for determining a concentration of a predetermined gas in a measurement volume. The gas sensor comprises a light source and a detector arranged to receive light that has passed through the measurement volume. During a first measurement period, the detector is used to make a first measurement of an amount of light received in at least one wavelength band which is absorbed by the gas. The first measurement is compared to a predetermined threshold value. If the threshold is crossed, during a second measurement period the detector is used to make a second measurement of an amount of light received in at least one wavelength band which is absorbed by the gas. The concentration of said gas in said measurement volume is calculated using the first and/or second measurement.
Claims23
A method of operating a gas sensor for determining a concentration of a gas in a measurement volume, the gas sensor comprising a light source and a detector arranged to receive light that has passed through the measurement volume, the method comprising the steps of:
- during a lower energy consumption measurement period, using the detector to make a lower energy consumption measurement of an amount of light received in at least one wavelength band which is absorbed by the gas;
- comparing said lower energy consumption measurement to a threshold value;
- if said threshold value is crossed, during a higher energy consumption measurement period using the detector to make a higher energy consumption measurement of an amount of light received in at least one wavelength band which is absorbed by the gas;
- and
- calculating the concentration of said gas in said measurement volume using the lower energy consumption and/or the higher energy consumption measurement;
- wherein the gas sensor comprises a temperature sensor, the method further comprising using a temperature of the gas sensor to configure one or more of a length of the higher energy consumption measurement period, a sampling rate at which the higher energy consumption measurement is carried out or an intensity of the light source during the higher energy consumption measurement period.
A gas sensing system including a gas sensor for sensing a gas comprising a light source, a measurement volume and a detector arranged to receive light that has passed through the measurement volume, the system being arranged to:
- during a lower energy consumption measurement period, use the detector to make a lower energy consumption measurement of an amount of light received in at least one wavelength band which is absorbed by the gas;
- compare said lower energy consumption measurement to a threshold value;
- if said threshold value is crossed, during a higher energy consumption measurement period using the detector to make a higher energy consumption measurement of an amount of light received in at least one wavelength band which is absorbed by the gas;
- and
- calculate the concentration of said gas in said measurement volume using the lower energy consumption measurement and/or higher energy consumption measurement;
- the gas sensor further comprising a temperature sensor and wherein the gas sensing system is arranged to use a temperature of the gas sensor to configure one or more of a length of the higher energy consumption measurement period, a sampling rate at which the higher energy consumption measurement is carried out or an intensity of the light source during the higher energy consumption measurement period.
The gas sensing system as claimed in 21, wherein the adaptable filter comprises a micro-electromechanical system.
Dependencies are inferred from the claim text.