SANSEL pH 641 Online pH / ORP Indicator is a compact and rugged panel mount instrument designed for accurate pH and ORP measurement in industrial applications. Built with a weatherproof enclosure and precision sensing circuitry, the instrument provides dependable performance in demanding process environments. The pH 641 supports easy front panel calibration using 4pH and 7pH buffer settings along with zero and span adjustment for ORP measurement, simplifying routine maintenance and calibration procedures. Operating on a universal 90V to 270V AC/DC power supply, this online indicator is ideal for chemical industries, water treatment plants, food processing facilities, and environmental monitoring systems where continuous pH and ORP indication is essential.