20056 MicroTOL 3 Online Turbidimeter 0 – 100 NTU (90 – 250VAC). Ultrasonic Auto Clean for Finished Water. IR light source for ISO 7027 certification. Also includes: Ultrasonic Auto Clean, Back Light Display,RS-485 with Modbus Protocol Leading edge Microprocessor Technology combined with 35 years of optical measurement expertise has allowed HF scientific to become the leader in regulatory reporting turbidimeters. The HF Micro OL OnLine Turbidimeter has been specifically designed to meet regulations of the EPA 180.1 and ISO 7027. Features include fast and easy calibration, verification in seconds, low maintenance, fail safe design which ensures the instrument is always reading accurately, bubble rejection system, optional ultrasonic autoclean system, and a data acquisition software system that allows logging and data storage for multiple turbidimeters.