Sybron Barnstead MEGOHM-CM PM-520 Purity Meter Controller

Sybron Barnstead MEGOHM-CM PM-520 Purity Meter Controller is a legacy control module designed for use with Barnstead water-purification systems to monitor water purity. The MEGOHM-CM designation signals its focus on resistivity-based purity measurement, expressed in megohm-centimeters (MΩ·cm), a key metric for laboratory-grade water quality. As a Purity Meter Controller, the PM-520 interfaces with the associated purity meter to display and respond to the water’s purity reading, helping operators verify that product water meets stringent quality targets before use in analytical or biological workflows. This unit is commonly associated with older Barnstead purification configurations, where a dedicated purity monitor and controller formed part of the core water-cleaning train, supporting routine calibration, monitoring, and validation of resistivity as a proxy for purity in laboratory applications. In practice, it serves as a replacement component for compatible Barnstead purification setups in laboratories requiring high-purity water.