Redundant OptoAcoustic Technology for Genuine Monitoring
OptoAcoustic gas detection determines gas content via the measurement of acoustic pressure waves that are propagated as a gas is irradiated under an appropriately tuned light. A gaseous mixture diffuses through a membrane into a measurement cell, which contains an optical light source and a microphone. Incident light modulated at a specific frequency is briefly absorbed as intermolecular energy by the gas molecules and then released as translational energy, creating periodic temperature and pressure changes that generate measurable acoustic pulses.

The novel dual-cell detector (Patent # US 7,213,444 B2) is comprised of two separate and identical cells that act interchangeably either as the primary gas-measurement cell or as a secondary compensation or reference cell. The secondary cell is also used as a redundancy measure - Industry’s First Redundant Gas Detector with active sensing element plus backup sensing element - in the event of primary cell failure.

The failsafe gas sensor has been engineered to sustain harsh conditions at gas gathering & processing facilities, compressor stations, drilling and production platforms or gas wells, oil refineries, chemical/petrochemical installations as well as LNG, NGL, LPG and propane plants, where they withstand vibration, temperature, and humidity extremes. The factory-calibrated sensor, with an operational lifetime of minimum 15 years, requires less routine maintenance due essentially to its total immunity, embedded self-diagnostics, false alarm rejection and temperature compensation algorithms.

The compensation of deceptive signals is achieved by subtracting the reference signal (reference cell which is not irradiated, and thus gas inactive) from the measurement signal (the irradiated cell, thus the gas active cell). Once the primary cell reaches its lifetime, the second cell takes over, seamlessly. The primary cell, which becomes the gas inactive cell, is now the new reference cell. Simultaneously, the secondary cell becomes gas active and thus the new measurement cell. The switch from the first to the second sequence of operation – Sequential Redundancy - occurs automatically within few seconds, relying essentially on the sensor self-diagnostics features of the gas sensor. This represents the unique combination of necessary compensation and valuable redundancy in one single gas sensor!