Gassonic Observer i Ultrasonic Gas Leak Detector

Precision Safety supply and support the proven Gassonic Observer Ultrasonic Gas Leak Detector.
Technologies that have traditionally been used in fixed installations to detect hydrocarbon gas leaks, such as Catalytic/IR Point Sensors and IR Open Path Sensors all have one limitation: in order for a leak to be detected, the gas itself must either be in close proximity to the detector or within a pre-defined area.
Unfortunately, outdoor environmental conditions such as changing wind directions and quick dispersion of the gas cloud from a leaking outdoor installation often cause traditional gas detection systems to fail simply because the gas never reaches the detector.
Ultrasonic Gas Leak Detectors (UGLD) respond at the speed of sound at gas leak initiation, unaffected by changing wind directions and dilution of the gas.
The Gassonic Observer i Ultrasonic Gas Leak Detector is the world’s first gas leak detector equipped with Artificial Neural Network (ANN) real-time broadband acoustic sound processing technology. This technology is based on extensive studies and real recording of gas leak sounds and industrial background noise from a wide array of industry sources over the years. The ANN algorithm has been “trained” with these recordings to automatically distinguish between unwanted acoustic background noise and dangerous gas leaks.
The Gassonic Observer i Prevents False Alarms Experienced with other UGLD's
How the Observer i Prevents False Alarms
The Gassonic Observer i is a third generation of Ultrasonic Gas Leak Detectors that now uses Artificial Neural Network (ANN) algorithms in the detector’s advanced sound processing design to distinguish between real gas leak noise and unwanted background noise.

Artificial Neural Network (ANN) used by the Gassonic Observer i UGLD
An essential performance parameter for an Ultrasonic Gas Leak Detector is to ensure high acoustic sensitivity to real gas leaks over a large area, while at the same time minimizing the interference from background noise sources unrelated to gas leaks.
Artificial Neural Network (ANN) algorithms in the detector’s advanced sound processing design to distinguish between real gas leak noise and unwanted background noise. The ANN uses a mathematical algorithm to search for familiarity in large and complex sets of data.

SENSSONIC Acoustic Self-Test Technology
The SENSSONIC self-test technology provides a full acoustic integrity test of the Observer i Ultrasonic Gas Leak Detector. This occurs every 15 minutes, using a high-quality sound transducer transmitting an air-borne ultrasonic signal to the detector’s microphone system.
This self test ensures that the microphone and the electronics are tested continuously within well-defined tolerances, and that the operator is warned if the detector should fail this regular test. The SENSSONIC technology provides reliable and fail-safe operation for the Observer i Ultrasonic Gas Leak Detector, protecting your assets and ensuring human safety in your industrial facility.
What Makes ANN So Special in the Observer i UGLD
With ANN technology, the GASSONIC OBSERVER-i makes it possible to fully analyze the sound spectrum as low as 12 kHz since common high pass filters are not used. This provides a broader leak detection range which also increases sensitivity to smaller gas leaks, without interference from unwanted background noise. ANN technology enables the GASSONIC OBSERVER-i to be installed without time consuming “training” sequences, and provides industry-leading detection distance, with unprecedented suppression of false alarms.
In addition, ANN technology ensures that the GASSONIC OBSERVER-i hasthe same gas leak detection coverage in high and low noise areas. The device requires no alarm set points or trigger levels to be configured, nor do these alarm parameters need to be adjusted if background ultrasound were to increase or decrease over time.
Delivered Across Australia & NZ Direct From Sydney, Melbourne or Perth Warehouses
The only Ultrasonic Gas Leak Detector that can be Calibrated in the Field
1701 Portable Calibrator for the Gassonic Observer H and Observer i Ultrasonic Gas Leak Detectors

The 1701 is a portable test and calibration unit used to verify the operation and calibrate the Gassonic Observer i ultrasonic gas leak detectors. Although the detectors do not require regular maintenance, the 1701 can be used to satisfy the requirements for regular plant maintenance. Further, the 1701 requires no electrical connection to the gas leak detector but is simply placed over the sensor head of the gas leak detector.
Test Function
The test function in the 1701 is for traceable testing of GM UGLD. In test mode, the 1701 emits a constant calibrated sound that the ultrasonic gas leak detector responds to. On the Observers and EX-5,the sound level emitted from the 1701 appears on the display of the detector and on the Surveyor, the trigger level is displayed on the 1701.

Calibration Function
The Observer i UGLD can be re-calibrated on-site. When calibrating the detectors, the portable test and calibration unit emits a series of ultrasonic sound levels at different amplitudes. It then automatically performs a zero and a span calibration of the detector.
Step Function
For more accurate testing, a step test can be performed on the Observers where the dynamic range from 44 dB to 101 dB can be tested in 1 dB steps.
Delay Test Function of the Gassonic UGLD
During the delay test function, a constant sound level is emitted from the 1701. The purpose of this function is to test the GM ultrasonic gas leak detectors after they have been installed with either the built-in delay function enabled or an external delay function.
The 1701 delay test function permits users to verify the complete signal transmission from the detector head into the fire and gas panel or the DCS system
- Instantly detects pressurized gas leaks at the speed of sound utilizing Gassonic technology
- ANN technology distinguishes real gas leak noise from background noise, suppressing false alarm sources
- Does not require in-field training, fully operational after installation
- Detects gas leaks from 2 BAR (29 psi) pressure for rapid detection of small leaks
- Patented Senssonic™ self-test ensures full failsafe operation
- Trouble-free maintenance and one-person check and calibration
Detector Type | Ultrasonic (acoustic) gas leak detector |
Background Noise Rejection Method | Artificial Neural Network (ANN) |
Min. Acoustic Det. Frequency (ANN Mode) | 12 kHz |
Min. Detection Limit | 40 dB (u) |
Accuracy | ±3 dB |
Self-test | Performed every 15 minutes |
Min. Pressure Requirement | 2 BAR (29 psi) |
Detector Coverage (ref. Methane) | Enhanced Mode (ANN) (@ 0.1 kg/sec): FQHI setting (59 dB ANN sensitivity level): 17 meters (56 ft.) Default Ultra-high to medium background noise FQLO setting (54 dB ANN sensitivity level): 28 meters (92 ft.) Medium to low background noise Classic Mode (@ 0.1 kg.sec): Ultra-high: 7 meters (23 ft.) w/84 dB T.L. High: 12 meters (39 ft.) w/74 dB T.L. Medium: 18 meters (59 ft.) w/64 dB T.L. Low: 24 meters (79 ft.) w/54 dB T.L. |
Response Time | < 1 s (speed of sound) |
Approvals Classification | ATEX/IECEx: Ex d ia IIB+H2 Gb T6, Ex tb IIIC T85°C Db (Ta = –40°C to +60°C) CSA: Ex d ia IIB+H2 Gb T6, Ex tb IIIC T85°C Db FM/CSA: Class I, Div. 1, 2 Groups B,C,D; Class II, Div. 1, 2 Groups E,F,G; Class III, T5 (Ta = –40°C to +60°C) |
Warranty | 2 years |
Input Power | 15–36 VDC, 250 mA max. 24 VDC, 170 mA nominal |
Relay Ratings (optional) | 8 A @ 250 VAC |
Current Output (sink or source) | Status Indications: 0 mA: Start up, no power 1 mA: Pulsed acoustic error 3 mA: Unit inhibit Classic Mode: 4–20 mA, 40–120 dB (u) ANN Mode: 4–12 mA, 40–120 dB (u) 16 mA, warning 20 mA, alarm |
EMC/RFI | EMC Directive 2004/108/EC EN 61000-6-2, EN 61000-6-4 |
Serial Digital Communication | HART, Modbus |
Cable Requirements | Max. cable length between Observer-i and power source @ 24 VDC (20 ohm) 2.08 mm2 (14 AWG) – 1,809 m (5,928 ft) |
Housing | Stainless Steel AISI 316L |
Dimensions | 203 x 203 x 201 mm |
Weight | 7.5 kg |
Conduit Entries | M20 x 1.5 |
Mounting Holes | 2 x mounting screws – M8 x 19 max |
Ingress Protection | IP66 |
Observer i UGLD Data Sheet
Vie more information on MSA’s Website
Contact us
1300 189 146
Australia & New Zealand
sales@precisionsafety.com.au
