The LasIR -- A near infrared system for monitoring air pollution and some measurements of HF in aluminum smelters

The LasIR system of instruments provide a way of measuring HF and other gases with no interferences from other gases. Since they are based on laser diodes operating in the communication region of the near infrared, they are rugged, easy to operate and relatively small and inexpensive. They are highly sensitive and can make measurements continuously with response times of less than 1 sec. The instrument can be located in any desired location where it is free of environmental constraints and is readily available for servicing if required. The monitoring beam is transmitted to the measuring location by fiber optics. These measurement locations can be up to several kilometers distant from the control. Three versions of the LasIR are available, the LasIR-S for in stack monitoring; the LasIR-R for potroom or perimeter monitoring; and the LasIR-P for point source measurements when looking for local leaks Multiplexing can be used to operate, simultaneously, a combination of a number of these versions from the same instrument at a number of locations. Examples of the application of these systems for measuring HF in aluminum smelters have shown that there is ample sensitivity to measure HF both in the stacks and in the pot-roomsmore » of these smelters« less