Electro-Chemical Devices (ECD) DCA-23 - Manual (Page 23)

DCA-23 Page 17
6.0 TROUBLESHOOTING
The DCA-23 was evaluated and calibrated at the factory before shipment. Upon initial start up the
system should require minimal to no adjustments.
Verify the system has sample flow and the pH and the temperature sensors are reading correctly. These
parameters affect the measurement and must be reading properly. If these conditions are met and
problems still exist use the Troubleshooting Table to find a remedy.
Troubleshooting Guide
Symptom Possible Cause Remedy
Displayed value is Higher
than DPD test value.
pH sensor reading to high
TRO sensor reading to high Check mV value in pH 7
buffer, if > -60 mV replace the
electrode cartridge. If < -60mV
perform a one pt. Cal
Check the TRO value vs. the
tested DPD chlorine value on
Calibration Curve. Correct if
necessary.
Displayed value is Lower than
DPD test value
pH sensor reading to low
TRO sensor reading to low Check pH of grab sample and
standardize the pH reading
Check the TRO sensor in a
ORP standard solution, if
more than 60 mV low then
replace the electrode, other-
wise recalibrate to DPD test.
Zero Chlorine Reading in a
solution with measureable
chlorine.
TRO sensor electrically
shorted Check TRO sensor in a ORP
standard solution
Electrode failure or sealing o-
ring failure. Remove electrode
cartridge from sensor and
look for water inside the
sensor, replace electrode and
sensor if water inside.
Unstable Chlorine Reading
Mostly Air bubbles in line
Oscillating pressure > 5 psi
Coating on pH or TRO sensor
Remove air from line.
Dampen pulses with
accumulator before flow cell
Oil or grease on pH or TRO will
cause noisy readings, clean
electrode tips with detergent