5
Digital pH Meter
40
Example: if previous calibration was at pH 4.01,
7.00, and 10.01, and you re-calibrated pH 7.00
only, the old calibration data at pH 4.01 and pH
10.01 will be retained.
See Program P2.0 in the SETUP to view current
calibration points. To completely re-calibrate, or after
replacing the probe, it is best to reset the meter
to factory defaults and re-calibrate at all points.
Preparing the Meter for Calibration
Before starting calibration, make sure you
are in the correct measurement mode.
Temperature Calibration
The temperature sensor is factory calibrated.
Calibrate your sensor only if you suspect
temperature errors may have occurred over a long
period of time or if you have a replacement probe.
1
Connect the temperature sensor.
2
Switch the meter on. ATC will appear at
the bottom right-hand corner of the LCD.
3
Press
MODE
to select pH mode.
4
Press
CAL/MEAS
. The CAL indicator appears.
5
Press
MODE
to enter temperature calibration mode.
6
Dip the electrode into a solution of known
temperature (i.e. a temperature bath). Allow time
for the built-in temperature sensor to stabilise.
7
Scroll with
Mil
or
MRI
to set the correct
temperature value (i.e. the temperature of
the temperature bath).
8
Press
ENTER
to confirm. The meter will be
calibrated and return to the measurement mode.
Note:
To exit without confirming the
temperature calibration value, press
CAL/MEAS
.
NOTE:
If the ATC does not light up, see
SETUP menu Program P1.3 to switch it on.
NOTE:
The maximum temperature
offset is ±5°C from original reading.
5.5 Error Messages and Troubleshooting
Error message/Problem
Possible Cause
Corrective Action
Err. Annunciator
Wrong input in
selected mode
Release key. Select valid
operations depending on mode
Secondary Display toggles continuously
between Calibration Buffer Values, Electrode
icon blinks and Err Annunciator lights up
Incorrect buffer used in
calibration or contaminated
buffer solution
Check if correct buffer used,
replace with fresh buffer if
where necessary
Battery icon illuminated
Low battery
Replace with new batteries as soon as possible
Blank display when
ON/OFF key is selected
1
Batteries not in place
2
Batteries not aligned
to correct polarity
3
Low level batteries
1
Insert batteries
2
Insert batteries to correct polarity position
3
Replace batteries or connect to AC adaptor
Unstable reading
1
Insufficient reference
electrolyte in electrode
2
Broken electrode
3
External electrical noise
caused by nearby motor
4
Dirty electrode
1
Refill electrode with reference electrolyte
2
Replace electrode
3
Move location or switch
off interfering device
4
Clean or rejuvenate electrode.
Recalibrate meter after cleaning electrode
Slow response
Dirty/oily electrode
Clean electrode. Rejuvenate if necessary
Meter not responding to key press
1
HOLD mode in operation
2
Internal program error
1
Cancel HOLD mode
2
Reset all internal programs
by re-inserting batteries
