YSI EcoSense pH100M [601031] pH/ORP/mV/Temperature (Instrument Only). The YSI EcoSense pH100M pH/ORP Meter provides the most accurate data in the most affordable format. The instruments feature an easy-to-use interface, one-hand operation, IP67 waterproof case, and low cost of ownership over the life of the product. With a micro-USB port for transferring data to a PC (no software required), this YSI unit also features a memory that can hold up to 250 data sets. The pH100M is designed for quick, accurate results in an economical platform. The ability to measure pH, mV/ORP, and temperature in a simple, compact handheld allows the instrument to be used in multiple applications. With a one-year instrument warranty, six-month electrode warranty, calibration backup, and a variety of cable/sensor options (glass bulb, flat tipped, and piercing tipped), the pH100M will fit your needs.