Process Photometers

Process Photometers

Process photometers are inline optical instruments used to measure absorbance and turbidity for real-time concentration, color, and quality monitoring. By selecting UV, visible (VIS), or near-infrared (NIR) wavelengths and suitable optical path lengths, these systems target specific analytes or product properties without requiring continuous sampling to the lab.

Absorbance measurement follows Lambert–Beer behavior: light transmitted through the medium is measured and converted into absorbance units or optical density by the transmitter. For turbidity-related duties, scattered-light techniques are applied, including forward-scatter methods that provide rapid detection of filter breaks and subtle clarity changes. Hygienic mechanical design and high temperature/pressure capability support use in demanding process environments.

Inline photometry reduces time spent sampling and minimizes contamination risk associated with off-line testing. Reagent-free optical measurement lowers consumable dependence and reduces cross-sensitivity compared with chemical methods. Certified calibration filters and optimized low-volume flow cells further support stable measurement, faster response, and improved product yield.

Typical applications include chromatography monitoring, fermentation tracking, filtration control, phase separation supervision, and crystallization process stability. High-temperature and high-pressure stability also support condensate monitoring and heat exchanger leak detection, where early detection of contamination protects downstream equipment and product quality.

Successful deployments match wavelength and measurement method to the process objective, select appropriate hygienic connections and flow cells, and incorporate window cleaning strategies where coating risk exists. Photometers can also be combined with complementary sensors (such as pH, conductivity, or oxygen) on multiparameter transmitter platforms to consolidate quality monitoring at critical process nodes.

Engineered Equipment Company, a leading supplier of specialized industrial equipment.