Metrohm 781 pH/Ion Meter User Manual
Page 126
8.2 Messages
116
780/781 pH/Ion Meter, Manual
Message
Situation
Cause
Remedy
XXX bytes
missing
Method storing
XXX bytes are missing for
saving a method
Press
<QUIT>
to delete
old methods
V add too
large
Conc calibration,
standard addition
Standard volume to be
added is larger than buret
volume
•
Use larger buret
•
Reduce start volume
•
Increase standard con-
centration
V add too
small
Conc calibration,
standard addition
Standard volume to be
added is too small
•
Check parameters (see
Section 6.5.5 or 6.6.1)
•
Reduce standard con-
centration
•
Use smaller buret
check working
cond.
Standard addi-
tion,
sample addition
No change in potential
after standard addition
Check standard addition
Strongly drifting electrode
signal
Check electrode
Slope sign incorrect for
type of ion
Check ion parameters under
evaluation er-
ror
Conc calibration,
standard addition,
sample addition
Evaluation not possible
•
Check parameters
•
Check standards
please wait
Report output
New task was started dur-
ing report output
Wait for report output
delta T >2 °C pH calibration,
Conc calibration
Temperature difference
between two buffers or
standards is too large
1. Match temperatures
2. Continue with
<ENTER>
or cancel
with
<MODE>
and re-
start
Electrode test
Temperature difference
between two buffers is too
large
1. Cancel electrode test with
<MODE>
2. Restart with suitable buff-
ers
check elec-
trode
Temperature
measuring
Short circuit or interruption Remedy fault or change
mode
electrode test
not passed
Electrode test
Electrode test gives values
outside the tolerances
see
validate in-
strument
Instrument has
been switched on
Set validation interval has
expired
1. Validate instrument
2. Reset time counter to ze-
ro (see
same buffer
pH calibration
Potential difference be-
tween 1st and 2nd buffer is
too small
1. Change buffer
2. Press
<ENTER>
same standard Conc calibration
Pot. difference between 1st
and 2nd standard < 6 mV
1. Change standard
2. Press
<ENTER>