The 8900 Multi-Parameter Controller is field-commissioned with a user-specified combination of inputs, outputs and relays using easy-to-install modular boards within the base unit. The GF transmitters and controllers support GF Signet Flow, pH/ORP, Conductivity/Resistivity, Salinity, Temperature, Pressure, Level, Dissolved Oxygen and devices that transmit a 4 to 20 mA signal with the use of the 8058 iGo® Signal Converter.