pH calibration
This instrument is capable of up to 3-point pH calibration to ensure accuracy across
the entire pH range of the meter. You can perform 1-, 2-, or 3-point calibration with
standard pH buffers 4.00; 7.00 and 10.00.
We recommend that you perform at least a 2-point calibration using standard
buffers that bracket (one above and one below) the expected sample range. You can
also perform a 1-point calibration, but make sure that the buffer value is close to the
sample value you are measuring.
This meter features three preprogrammed pH buffers (pH 4.00, 7.00 and 10.00).
The meter automatically recognizes and calibrates to these standard buffer values,
which makes pH calibration faster and easier. See pages 22-23 for information on
our high-quality OAKTON pH buffers.
10
Calibrating for pH:
1.
If necessary, press the MODE key to
select pH mode
. The pH indicator
appears in the upper right hand corner
of the display.
2.
Rinse the probe thoroughly with
de-ionized water or a rinse solution.
Do
not wipe the probe; this causes a build-up
of electrostatic charge on the glass surface.
3.
Dip the probe into the calibration buffer.
The end of the probe must be completely
immersed into the sample. Stir the probe
gently to create a homogeneous sample.
4.
Wait for the measured pH value to
stabilize.
The READY indicator will
display when the reading stabilizes.
See figure
5.
Press CAL/MEAS
to enter pH calibration
mode. The primary display will show
the measured reading while the smaller
secondary display will indicate the pH
standard buffer solution.
See figure
NOTE:
If using a pH buffer other than pH 7,
press the
▲
or
▼
keys to scroll up or
down until the secondary display
value is the same as your pH buffer
value (pH 4.00, 7.00 or 10.00).
A
pH
ATC
CAL
pH
pH
4.3
B
pH
ATC
READY
MEAS
C
A
B
11
pH
ATC
READY
CAL
pH
pH
ATC
pH
pH
6.
Wait for the measured pH value to
stabilize.
The READY indicator will
display when the reading stabilizes.
See figure
7.
After the READY indicator turns on,
press ENTER to confirm calibration
.
A confirming indicator (CON) flashes
and disappears. The meter is now
calibrated at the buffer indicated in the
secondary display.
See figure
The secondary display automatically scrolls
to the next buffer calibration option.
• If you are performing multipoint
calibration, go to step 7.
• If you are performing one-point
calibration, go to step 10.
8.
Press the
▲
or
▼
keys
to select the
next buffer value you want to calibrate
(pH 4.00; 7.00 or 10.00).
See figure
9.
Rinse the probe with de-ionized water
or a rinse solution, and place it in the
next pH buffer.
10.
Follow steps 5 to 8 for additional
calibration points (up to 3 values).
11.
When calibration is complete,
press CAL/MEAS to return to pH
measurement mode
.
Notes
To exit from pH Calibration mode without
confirming calibration,
DO NOT press
ENTER in step 6. Press CAL/MEAS instead.
If the selected buffer value is not within
±1.00 pH from the measured pH value:
the electrode and buffer icon blink and the
ERR annunciator appears in the lower left
corner of the display. These indicators also
flash if the buffer used is not the same as
the buffer value on the secondary display.
C
pH
ATC
READY
CAL
CON
pH
pH
ATC
READY
CAL
CON
pH
pH
pH
ATC
CAL
pH
pH
ATC
CAL
pH
pH
E
D
C
D
E
