Gas leak detector for drilling rigs and platforms

Paul Boughton

The advanced Gassonic Observer-H Ultrasonic Gas Leak Detector from General Monitors has obtained approval through the Bureau Veritas Marine Division under the rules for the classification for steel ships.

Approval to the BV NR467 standard for steel ships assures General Monitors’ customers that the Observer-H has undergone third-party testing and is compliant with international regulations, ensuring product quality and safety and facilitating trade.

The Gassonic Observer-H Ultrasonic Gas Leak Detector is suitable for gas leak detection in pressurised systems. The Gassonic Observer-H features HART communications, Modbus with single and block transfer modes, Emerson AMS Intelligent Device Manager support, and event logging. In addition to BV certification, the Observer-H is ATEX, IECEx, FM and CSA hazardous area certified and SIL 3 suitable.

The Gassonic Observer-H is suitable for gas detection in open, well-ventilated areas, where traditional detection methods may be unsuitable or dependent on ventilation. It detects gas leaks by sensing the airborne ultrasound emitted from leaking gas at high pressure. Since the gas leak detector responds to the source of a gas release rather than the dispersed gas, it is unaffected by changing wind directions, gas dilution, and the direction of the leak. The Gassonic Observer-H’s wide coverage zone makes it possible to supervise areas up to a 20 meter radius, for the detection of leaks as small as 0.1 kg/sec., with only one device.

Designed for failsafe operation, the rugged Gassonic Observer-H features robust microphone technology with an advanced stainless steel microphone. The detector also offers the Senssonic integrated acoustic self-test, which verifies the integrity of the instrument’s electric circuit and microphone every 15 minutes. It features stainless steel, AISI 316L explosion-proof housing, offering corrosion resistance in the harshest environments.

Featuring a sophisticated high pass filter to remove frequencies below 25 kHz, the Gassonic Observer-H  effectively eliminates interference from audible sound. At the same time, setting the alarm trigger level above the ultrasonic background noise ensures the detector accurately detects gas leaks. The Observer-H is equipped with a three-digit LED display and an event logging function that stores fault, sound check, calibration, and alarm event history.

The versatile Gassonic Observer-H can be configured with an analog output or Modbus or HART communications to provide complete status and control capability in the control room. The Modbus and HART data can also be used for predictive maintenance and to enable asset management and process improvement.

The Gassonic Observer-H detects leaks at a frequency range of 25-70 kHz at a dynamic range of 58-104 dB. Detection coverage varies from 13-20 m radius in very low noise areas (<58 dB), 9-12 m radius in low noise areas (<68 dB), to 5-8 m radius in high noise areas (<78 dB). Such distances are defined for a methane gas leak of 0.1 kg/s.

The Gassonic Observer-H operates at a temperature range of -40°F to 140°F (-40°C to 60°C) and at a humidity range of 10 to 95% RH.

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