The Hamilton VisiFerm Optical Dissolved Oxygen product line has two interface outputs depending on the application.
ECS: ECS is an abbreviation for Electro Chemical Signal. VisiFerm sensors with an ECS output transform the measurement into a nano-amp (nA) output that mimics a traditional polarographic dissolved oxygen sensor. ECS interface is a good choice to replace polarographic sensors connected to pre-existing bio-controllers or transmitters. A temperature output from a NTC 22kOhm sensor is also included to perform compensation within the external electronics. Hamilton has cables and wiring diagrams for connection to many of the manufacturers of these products.
RS-485: VisiFerm RS-485 Dissolved Oxygen Sensors have a built-in microtransmitter within the sensor. The output of these sensor is either 4-20mA analog output or a Modbus RTU digital signal. Arc technology performs temperature compensation as well as adjustments for pressure and salinity within the sensor. The output signal is therefore fully compensated. VisiFerm Arc sensors can be directly connected to the Process Control System (PCS) without the need for a secondary transmitter. For customers looking for full digital integration, please consult the Arc Programmers Manual for additional Modbus configuration and communication information.
All VisiFerm sensors require external power to perform the measurement and provide an output signal. This power may be provided directly from the PCS or through a powered cable. Configuration and calibration of the VisiFerm sensor is accomplished through ArcAir software.