Diode laser gas analyser

Siemens has further developed its TDL technology with the Sitrans SL diode laser gas analyser featuring an inline reference cell filled with a non-interfering reference gas allowing for a fast and non-contact measurement of gas concentrations in process or flue gases. The Sitrans SL can be used in various industry and applications, such as process control in the chemical industry, process optimisation within the steel industry and as combustion control for boilers and municipal waste incinerators. The Sitrans SL is also an effective device for measuring minimum or maximum concentration limits for oxygen in explosive-proof environments.

The measuring principle of the Sitrans SL is based on the specific light absorption of different gas components using light from a laser diode that is sent from the transmitter through the process gas to the detector on the receiver side. As the bandwidth of the laser light is narrow, only the gas component of interest will interact with it. Other process influences, such as dust and temperature, are easily eliminated since the characteristics of the laser allow single-line spectroscopy free of interferences.

The Sitrans SL consists of a cross-duct sensor pair — transmitter and receiver — that are mounted directly on the process with no need for sampling systems and are designed for operations in harsh environmental conditions. There are no calibration gases required, which is a large cost saving both in expensive gas bottles and time offline for recalibration. The entire analytical instrument is fitted into these two enclosures, which are interconnected with one cable. Another cable is connected from the receiver providing the power and the customer interface.