The BT-55 series of brightness transmitters are intended for monitoring and control of bleaching chemicals, optical brightening agents and dyes in mechanical and chemical pulps, recycled fiber and paper machine applications. The transmitters feature, according to BTG, a low-maintenance probe and are standardly equipped with a UV light source for fluorescence measurement.The new transmitters are intended for optimizing chemical addition, minimizing product variability and reducing operational costs.The BT-55 series comprises three versions, BT-5500, BT-5510 and BT-5520, hence meeting most installation requirements. /AA