On-line analysis tunes in
15 Jan 2000
A new process analyser from Rosemount Analytical is said to `go far beyond the realms of conventional infrared techniques'. The AOTF-NIR instrument uses a patented acousto-optic tuneable filter (AOTF) coupled with fibre optics, to tune a near infrared (NIR) light beam to specific frequencies. When a light beam passes through the liquid in the sample cell, light not absorbed by the sample is transmitted back to the AOTF-NIR via the fibre optics. The transmitted light is rapidly tuned to selected NIR wavelengths by the AOTF and the instrument's processor calculates the concentration of the desired components.
A typical application has been in the pharmaceuticals industry. Here the analyser has been used to cut the time needed to remove solvent from a product. By continuously monitoring the product, the AOTF analyser has removed a bottleneck from the process by allowing operators to determine when the product is actually dry.