There is no way to "turn off" an unused input on a DC402. If you leave the terminals open you will get error messages.
Connect a simulated sensor to the unused input to clear the errors. Use a resistor on 11-12 to simulate the temp sensor, 1000 ohms for PT1000, 100 Ohms for PT100. Simulate the same type temperature sensor that the other channel is using.
Use a resistance to simulate the cell that gives a conductivity reading within the range, usually 1000 ohms between 14-15 will work. Once you have connected the resistors the input the errors will clear.
Designed to accept two sensor inputs. Differential, ratio, deviation, % passage or % rejection can be indicated and/or transmitted.
Conductivity meters, analyzers and transmitters are used for continuous process measurement and monitoring of conductivity, resistivity, WIFI, demineralizer water, RO water, percent concentration, boiler blowdown and TDS.
Liquid analyzers are used for monitoring process chemistry including water quality, providing process optimization and control.
Process analyzers are used to determine the chemical composition or physical properties of substances involved in industrial processes.