Ph Sensor; Constant Head Flow Controller - ECD FCA-22 Instruction Manual

pH Sensor
When used in clean water, pH sensors require little maintenance. pH sensors do require periodic
calibration due to drift in the reference electrode as it ages. This aging causes the displayed pH value to
be higher than the true pH of the sample.
Check the sensor on a monthly basis, recalibrate if necessary. Clean or replace the pH sensor when it
becomes noisy and slow to respond.
If the sensor needs cleaning then it can be soaked in a dilute solution of HCl, 1‐5%, for 10‐30 minutes.
This will remove scale or biofilms from the sensor, rinse well and soak in pH 4 buffer for 15 minutes
before returning the sensor to service.
Constant Head Flow Controller (CHFC)
The CHFC is designed to provide a constant flow to the Free Chlorine Sensor (FCS) independent of
variations in the sample pressure. Decreasing the sample flow to the FCS will lower the output of the
FCS. In most clean water applications the CHFC requires no maintenance. The vertical position of the
central tube sets the Head Pressure of the system. It is set for optimal flow but lower flow rates can be
attained by adjusting its height.
On a monthly basis visually inspect the CHFC, the interconnecting tubing and the drain tubing for
obstructions or sediments that may reduce the flow. The CHFC and tubing can be easily disassembled
and cleaned with soap and water. Some dirty applications like Cooling Towers may require periodic
cleaning due to sediments.
Page 19
FCA‐22 Instruction Manual