16
5.2 Conductivity
Menu
The conductivity menu provides the following settings: Calibration, Self Test, Unit selection, and
sampling mode setup. Additional settings are also discussed below. Refer to figure 8, Conductivity
Menu Chart.
Calibrate
To Calibrate the conductivity, use either a hand held meter, or a buffer solution, and adjust the WCT controller to
match. Once Calibrate is entered, the unit continuously displays conductivity readings. Press an arrow key to change
the value displayed to match the hand held meter or the buffer solution. You must press ENTER to activate the new
calibration. You must press the EXIT key to exit calibration. The Bleed output is unaffected until the calibration
menu is exited, so if it was ON when you entered calibration it will stay on until you exit.
Self Test
Press ENTER to begin self test. Press any key to stop. Self Test internally simulates a conductivity sensor and
should always give the reading 1000 µS/cm ± 100 µS. If it does not, there is a problem with the electronics and unit
should be serviced. If the self-test is in the expected range, and there is a problem calibrating, then the sensor or its
wiring is at fault.
Units
You may choose to display conductivity in µS/cm or in ppm. Press ENTER and then use the Up and Down arrows
to change the units. If you change the units, you will be warned to check your settings. This is important. Set points
are not automatically translated from µS/cm to ppm. If you change the units you will need to change your Bleed
settings.
ppm C.F.
This is the ppm Conversion Factor (or multiplier). This is typically 0.666 but can be changed to accommodate
various requirements.
Sample
Mode C / I
Press enter to choose Continuous sampling or Intermittent sampling. A 'C' at the end of the display means that
sampling is continuous, while an 'I' indicates intermittent sampling. Use Continuous sampling with a traditional
bypass line installation of the conductivity sensor.
Choose Intermittent sampling to use the bleed solenoid valve for timed sampling of the conductivity.
Intermittent sampling installations read the conductivity at set intervals for a given sample duration. If the
conductivity is above the set point, the valve that controls the sampling will stay open until the conductivity falls
below the set point. If the time the valve stays open goes beyond the sample duration, the controller will display
Xtnd
on the top status line, as well as the amount of time extended. A limit on this amount of time may be
imposed; see Figure 10 Bleed Menu.
Continuous
Intermittent
If Intermittent sampling is chosen, the Flow Switch input will be ignored, and the following two settings will
become available:
Interval
This sets the amount of time between samples. This is set in Hours:Minutes.
Duration
This is the length of each sample. This is set in Minutes:Seconds.
RawCond
This menu is for information only and displays the temperature-compensated conductivity reading before the user’s
calibration has been applied.
