Innovative transmitter for combustible gases
IR transmitters have become recognised as reliable gas warning systems for explosion protection. They are used to detect individual combustible gases or a wide range of gases. This involves sending an IR beam with a certain light intensity through a measuring space and then capturing it with a detector. Parts of this beam are absorbed by, amongst other things, hydrocarbon molecules. The reduced light intensity of the beam is registered by beam detectors and converted into a signal as the existing gas concentration % LEL.
A special feature of our IR technology is its ability to also measure combustible gases above the bottom explosion limit (uniqueness). Moreover, the measurement does not require oxygen. With this technology there is basically no risk of contaminating the sensor, e.g. through silicone vapours or hydrogen sulphide when using catalytic combustion sensors.
Patented GfG technology
The internationally patented technology of the IR29 has been developed to solve the said problems. The gold-plated mirror optics of the sensor contains 2 radiators and up to 4 detector elements with different optical filters. The precisely calculated, microstructured and pure gold coated mirror optics of the IR29 are supplied for the first time without beam splitters. This helps to cut signal losses by 50 % and to completely avoid the physically-related disadvantages of a beam splitter. The measured values from two additional wavelengths (4 wavelengths in total) ensure improved detection of individual gases and thus enhanced selectivity. The result in the prevention of false alarms. Only a 4-wavelength system always guarantees early warnings and the simultaneous prevention of false alarms.
The IR29 is the first and only intrinsically safe IR gas transmitter with patented 4-beam 4-wavelength technology. The ignition protection class "intrinsically safe", which is so essential for industrial plants and the mining industry, is achieved by the additional use of the safety barrier SB1 and its internationally patented and innovative design.
Pressure sensor, moisture and temperature compensation
The measuring accuracy of IR sensors depends on partial pressure and thus also air pressure. Climatic fluctuations or barometric high pressure therefore influence the measuring result. Furthermore, the absorption spectrum of water almost completely covers that of hydrocarbon absorption in the 2.7 to 3.3 µm range. Air humidity therefore initially generates a measuring signal the same as the actual measuring gas. This cross-sensitivity is of particular importance in warm areas with high relative humidity. An increase in the absolute water absorption capacity of air is not linear with the temperature, i.e. three times as much water can be absorbed at 40 °C than at 20 °C. This influence can only be compensated if the current moisture content of the air is known. The IR29 can be optionally equipped with a pressure and moisture sensor for compensation.
The transmitter IR29 does not feature control elements for setting or servicing tasks. This helps to prevent accidental or unauthorised manipulation.
Service work at the transmitter IR 29 is carried out using the remote control RC 2.