Multi-spectral ultrasonic gas leak detector

An ultrasonic gas leak detector configured to discriminate the ultrasound generated by a pressurized gas leak into the atmosphere from false alarm ultrasound, comprising:

• a sensor system for detecting ultrasonic energy and providing sensor signals, the sensor system including a broadband sensor and a plurality of narrowband sensors having respective non-overlapping frequency responses, the broadband sensor and the plurality of narrowband sensors in close physical proximity and configured to receive acoustic signals from a distant gas leak and other acoustic sources;
• an electronic controller responsive to respective digital sensor signals each representative of corresponding respective sensor signals from the broadband sensor and the plurality of narrowband sensors, the electronic controller configured to provide:
• a preprocessing function including an algorithm configured for joint time frequency signal preprocessing the digital sensor signals to provide preprocessed signals corresponding to an ultrasonic frequency band;
• a sound pressure calculation function responsive to the preprocessed signals to provide computed sound pressure values representative of ultrasonic sound pressures sensed by the sensor;
• a threshold comparator function to compare the computed sound pressure values to a gas detection threshold value to determine whether the computed sound pressure values exceed the gas detection threshold value and provide a threshold comparator output indicating whether the gas detection threshold value has been exceeded;
• an Artificial Neural Network (ANN) function for processing the preprocessed signals and applying ANN coefficients configured to discriminate false alarm sources from gas leaks, and providing ANN outputs indicating an ANN decision whether a gas leak has been detected;
• an output function for generating detector outputs based on the threshold comparator outputs and the ANN output.

An ultrasonic gas leak detector configured to discriminate the ultrasound generated by a pressurized gas leak into the atmosphere from false alarm ultrasound, comprising:

• a sensor system for detecting ultrasonic energy and providing sensor signals, said system comprising a broadband sensor responsive to a broad band of ultrasonic frequencies, and at least one narrowband sensor having a peak frequency response within the broad band;
• an electronic controller responsive to respective digital sensor signals representative of each of the sensor signals from the broadband sensor and the at least one narrowband sensor, the electronic controller configured to provide:
• a computation function for generating sensor signal values representative of sensed ultrasonic energy;
• an Artificial Neural Network (ANN) function for processing signals derived from the digital sensor signals and applying ANN coefficients configured to discriminate false alarm sources from gas leaks, and providing ANN outputs indicating a decision whether a gas leak has been detected, the ANN outputs including at least two output states, wherein a first ANN output state indicates that a gas leak has been detected, and a second ANN output state indicates that a gas leak has not been detected;
• a system output function for generating detector outputs indicative of the ANN outputs and the sensor signal values.