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If the cell / probe factor is outside normal range (0.20- 0.70), 'WARNING' will be displayed.
If the cell / probe factor is excessive (< 0.01 or > 1.00), 'ERROR' will be displayed.
See Section 9, Fault Finding.
INPUT
TDS
CAL
(US / CM)
WARNING:
K = 0.75
SAVED
INPUT
TDS
CAL
(US / CM)
ERROR:
K = 1.00
SAVED
or
Note: If the calibration is accessed via the commissioning mode, the input voltage from the
probe circuit is displayed during 'CAL ..'. This ranges from 0 - 2.500 V and is used for diagnostic
purposes. The valve varies with conductivity, temperature and probe condition / installation.
Probe in blowdown line
The correct purge time needs to be selected first to ensure the sensor measures conductivity
at boiler temperature. Enter the valve of measured sample and press the
button. The
controller will start a purge cycle and record the conductivity of the boiler water at the end
of the purge time.
Probe in a CCD system:
We recommend that a competent water treatment company be consulted to establish the
most suitable conductivity level for individual plant. Conditions vary widely, as do the chemical
properties and conductivity of contaminants.
In many cases, the normal measured value of ‘clean’ condensate will be very low,
perhaps only 1 or 2 μS / cm in some cases, whereas the set point may be much higher,
perhaps 30 or 40 μS / cm.
To calibrate a CCD system, a liquid at approximately the maximum allowable
conductivity is introduced into the system. Use a mixture of tap water and condensate,
to simulate condensate at approximately the maximum allowable conductivity level (the
set point). 5 litres (1.3 US gallons) will be plenty for most systems. Use the Spirax Sarco
MS1 conductivity meter to check the conductivity. Close both stop valves and open the
drain valve and ‘water for flushing and calibration’ valve. Pour in the prepared water, and
let it run through the system until bubble free. Close the drain valve. Allow the display to
settle for two minutes.
Calibrate the controller as described in the main text. It is advisable to check calibration after
the system has been running for a few days, then periodically depending on the individual
plant conditions. Consult your water treatment specialist if in any doubt.
Note: Ensure purge time is set to zero and a Pt100 is installed.
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