8
ERROR DISPLAYS AND TROUBLESHOOTING
pH
LCD
Displa
ATC
Display
DISPLAY
Mode
Possible cause(s)
[Action(s)]
"ovr"
"ovr"
Measure
Temperature > 212 °F range.
[Bring solution to a
lower temperature.]
[Replace
electrode &
ATC assembly .]
"udr"
"udr"
Measure
Temperature < 14.2 °F range.
[Bring solution to a
higher temperature.]
[Replace
electrode &
ATC assembly .]
"udr" or
"ovr"
-14.2 to 212 °F
Measure
When pH value < 0.00 pH
(udr) or >14.00 pH (ovr)
[Over Range or Recalibrate.]
"ovr"
32.0 to 140 °F
pH CAL
a.pH-
OFFSET
b.pH-
SLOPE
a. Offset @ 7.00 pH:
mV > 100 mV Offset
Offset @ 6.86 pH:
mV > 108.3 mV
b. New slope>ideal
slope by 30%
[Use a new buffer
solution.]
[Replace electrode & ATC
assembly.]
"udr"
32.0 to 140 °F
pH CAL
a.pH-
OFFSET
b.pH-
SLOPE
a. Offset @ 7.00 pH:
mV < -100 mV
Offset @ 6.86 pH:
mV < 91.7 mV
b. New Slope < ideal
slope by 30%
[Use a new buffer
solution.]
[Replace electrode & ATC
assembly.]
"udr" or
"ovr"
14.2 to 212 °F
pH CAL
a.pH-
OFFSET
b.pH-
SLOPE
When buffer temperature <
32.0 °F (udr) or > 140 °F (ovr)
[Bring buffer temperature
within 32.0 to 140 °F range .]
