Manufactured by optek-Danulat Inc., the Control 4000 is a modular microprocessor-based photometric converter designed for the company’s ultraviolet, visible and near-IR absorption-based and scattered-light-based sensors. Features include an integrated data logger for quality control, simple menu-based software, advanced software tools, slope adjustment and remote process control functions. The high-contrast graphic display shows absorbance, transmittance and concentration in real time and in any unit of measure. The measurements also can be displayed as text, bar graphs or trend values. The software includes adjustable signal damping, 16 linearization tables and advanced calculation capabilities. The converter includes a factory zero point for scattered-light sensors and a secondary zero for additional offset.