Error description
The electrode slope is between –60 and
–65 mV and the 3 calibration values are
all significantly offset to the positive
range.
All mV values for the calibration data
only differ in the figures after decimal
separator (almost constant).
Refer to
Error description
fluctuate
The calibration values
excessively
The slope is between –40 and –45 mV
after the calibration
The slope decreases, the membrane
can be damaged. The values of the
electrode slope can decrease after
1–2 weeks to –40 mV and –50 mV.
A large continuous drift is on the
measured values (up to 2 mg in 24 h).
Fluctuations of measured values and
interference of the calibration in the
lower measuring range.
All three electrode values increase
within 24 h over 8 mV to positive values.
English
Table 8Error messages (continued)
Diagnostics
- The electrolyte is almost empty
- electrode body leaking
- Membrane cap leaking
- Amplifier board faulty
Table 9
for additional errors messages.
Table 9Additional error messages
Diagnostics
- Electrode faulty
- The measuring range 0.05–20 mg/L
NH
–N is adjusted and the wrong
4
standard solutions 10 and 50 mg/L
NH
–N are used.
4
- Membrane is damaged (for example
with silicone oil).
- Electrode cap is damaged. The
electrolyte crystallize on the cover/cap
and evaporate very quickly.
Insufficient sample when sample is
-
required for the determination of the
zero value
- The ectrolyte level dropped out below
4 mL.
Troubleshooting
Solution
- Electrolyte almost completely
evaporated after extended operation
- Tighten membrane cap
- Leaking electrode body: order new
electrode
- Fit new amplifier board
Solution
- Replace electrolyte and membrane
cap
- Insert the right standard solutions and
complete the procedure for changing
the measuring range in the service
menu.
- Remove the measurement chamber
completley
- Clean it thoroughly
- Re-new electrolyte
- Insert new electrode
- Make sure that sufficient sample is
available
- Empty the electrode body, rinse it with
distilled water and fill it with new
electrolyte.
31