OPSIS - Model 400FL -Fast-Loop System
If the gas duct is difficult to access or if it limits the length of the monitoring path too much, a System 400FL is a good alternative to the System 400CS. An insulated pipe is connected between the monitoring point and a separately located closed monitoring path (measurement cell). The outlet from the monitoring path is returned to the gas duct. The flow through the pipe and monitoring path can often be driven by the existing pressure drop in the flue gas duct, or a dedicated fan is fitted to the outlet of the measurement cell.
The flow through the pipe and measurement cell is normally high, which ensures that the gas being measured has the same composition as the gas in the flue. It is often possible to have long distances between the gas duct and the measurement cell, and a System 400FL can therefore also be an alternative if the optical fibre in a System 400CS would be too long.
As with the System 400CS, a System 400FL is normally built around an AR600 analyser. It can be complemented with an AR650 for the detection of even more types of gases.
