Gassonic Observer-H:
An Ultrasonic Gas Leak
Detector Available
with HART

General Monitors has launched a new ultrasonic gas leak detector available with HART, the Gassonic Observer-H. Based on the Gassonic Observer platform, the new product is equipped with Modbus and offers an event logging function to monitor warning, alarm, diagnostic, and maintenance events. The HART-enabled configuration of the Gassonic Observer-H supports Emerson's AMS Intelligent Device Manager. The AMS Suite can be used to track the Observer-H's key performance parameters.

The Gassonic Observer-H responds to ultrasound emitted by pressurized gas leaks over the ultrasonic background noise. The instrument offers 360-degree coverage over a radius that varies according to the level of ambient ultrasound. Assuming the minimum hazard to be detected is a methane gas leak of 0.1 kg/s, detection coverage ranges 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).

Although it is natural to try to infer the amplitude of ultrasonic noise from what one can hear, one should keep in mind audible and ultrasonic noise are uncorrelated. A room with noisy equipment may have low ultrasonic background noise and vice versa. Sound emissions vary across sources and obstructions may reduce (or amplify) sound at some frequencies more than at others.

To reduce the potential of false alarms, the Gassonic Observer-H features a sophisticated high pass filter that removes sound frequencies below 25 kHz, effectively eliminating 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.

At the heart of the instrument is the sensor itself, an advanced stainless steel microphone proven in over 10 years in the field. Combined with the Senssonic™ integrated acoustic self-test, which verifies the integrity of the instrument's electric circuit and microphone every 15 minutes, it provides reliable, failsafe operation. If the sensor is accidentally damaged or becomes obstructed, the instrument produces a fault.

Housed in a 316 stainless steel explosion-proof enclosure, the Gassonic Observer-H is designed for longevity in all types of environmental conditions. It operates at temperatures of -40°F to 140°F (-40°C to 60°C) and at a humidity range of 10 to 95% RH. It has ATEX, IECEx, FM, and CSA approvals for worldwide application and is IEC 61508 certified by FM as suitable for SIL 3 environments.

Links of interest
Gassonic Observer-H Ultrasonic Gas Leak Detector