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2.5 Troubleshooting
2.5.1 Probable causes and remedies are laid down in Table 2.1.
Table 2.1
Trouble and symptoms
Probable cause
Remedy
1 pH-meter is not powered up or
is de-energized once it is turned
on
Poor contact with power
supply
Open the dry cell
compartment and
clean contacts of
convertor unit, dry
cells or batteries
Supply voltage is below
2.2 V
Replace dry cells
or charge batteries
2 pH-meter readings are unstable Cable rupture or poor
contact in the electrode
cable connector
Check
for
safe
contact or repair
cable rupture
3 In measurements in different
buffer
solutions
apparatus
readings remain nearly the same
when pH-electrode (electrodes) is
transferred
from
one
buffer
solution into another one
Defective electrode (one
of electrodes)
Replace electrode
4 Temperature measured (under
normal use) differs from actual
value by more than 0.3
С
Defective
temperature
sensor
To be repaired at
factory
5
"WARNING! CALIBRATION
ERROR"
message on the screen
pH of the buffer solution
is
different
from
pH = 1.65 or pH = 9.18
Prepare
fresh
buffer solution
Cable rupture or poor
contact in the electrode
cable connector
Repair
rupture.
Ensure
safe
contact
Defective electrode
Replace electrode
6
"ROM
ERROR,
DEFECT
METER"
message on the screen
pH-meter
program
failure
To be repaired at
factory
7
"METER SETTINGS ERROR,
DEFECT METER"
message on
the screen
pH-meter
program
failure
To be repaired at
factory
8
"pH PROBE PARAMETERS
ERROR. ENTER рНi"
message
on the screen
pH-meter
program
failure
Enter рНi value
9
"pH
CALIBRATION
PARAMETERS
ERROR.
PERFORM
CALIBRATION"
message on the screen
pH-meter
program
failure
Calibrate