Background

Pictures of a working setup for the Honeywell UDA2182 dual analyzer that is controlling to a pH set point after a durafet probe and CO2/solenoids are installed. CO2 is injected into a header tank using a ozone injector.

Pictures

UDA2182 home screen Honeywell UDA2182 home screen

Relay - connected to solenoid that is normally closed UDA2182 relay settings, connected to a normally closed solenoid

Input - durafet probe UDA2182 input settings for the Durafet pH probe

Output - 4-20 mA output of pH value to external device UDA2182 4-20 mA output settings

The UDA outputs supply current (0-20 mA, see above). If the another system wants volts than you will need to convert the mA signal. You can do that using a converter board like this one (2 pack, move spacer on board to set output to 0-5V). The boards themselves will also need to be powered with a 12V DC power supply. This one should be able to handle two no issues. Once the signal is converted, 20 mA -> 5 V -> pH 14. (edited)

Setup the PID loop (older firmware version) UDA2182 PID loop setup, step 1 UDA2182 PID loop setup, step 2 UDA2182 PID loop setup, step 3 UDA2182 PID loop setup, step 4 UDA2182 PID loop setup, step 5 UDA2182 PID loop setup, step 6

Navigate to PID control screen UDA2182 PID control screen

The top pH on the top left is the Durafet values, the bottom left is the setpoint, and the bottom right is the activity of the solenoid (% open)

Press enter to open PID control menu UDA2182 PID control menu

Start PID loop

Video of the PID loop starting, recorded 18 Mar 2022 (also on YouTube).