USF Wallace & Tiernan DEPOLOX 4, Manual

Page: 50 / 113

15. ERROR MESSAGES
The following table shows and explains all the possible fault messages which may
appear on the dot-matrix display.
If several erros occur at the same time, the error messages are displayed successively
and repeated cyclically.
Once the fault has been cured, the measuring system automatically erases the message
from the dispaly.
ERROR MESSAGE CAUSE REMEDY
Flashing display Measured value outside Select bigger range.
measured value measuring range. Check calibration.
"mg/l", "pH" or
"mV"
*ZRO? Wrong connection of Check connection cables
measuring cell cable/max. and measuring cell current.
zero point compensation (Data sheet BZ-1145)
exceeded (± 5 µA for
Depolox 4 and > + 100 µA
for Depolox 3 systems).
*DPD? Slope error in chlorine Check measuring cell;
measurement amplifier. clean electrodes;
The difference between zero replace electrolyte;
current and measured value
check pH value of sample
is below 4 µA (min. value water (< pH 8?);
required for slope calibration check presence of
of full range). chlorisocyanurates (Cl
2
The max. current of 100 µA stabilizer) in sample water.
for Depolox 3 and 200 µA
for Depolox 4 is exceeded.
*CAL.? In the pH amplifier, the Check electrode,
tolerance of ± 100 mV was impedance transformer,
exceeded during pH 7.0 measuring cable and buffer
calibration (intersection of solution (use fresh solution!)
isothermal lines) or the
Replace electrodes.
tolerance of ± 4mV/ pH-value
was exceeded during slope
calibration (e.g. with pH 4.65
buffer solution).
In the Redox amplifier, the
tolerance of ± 50mV was
exceeded during calibration
with 468 mV buffer solution.
50