Calibration; Ph Calibration - LaMotte pHPLUS DIRECT 2 Manual

default) or the last calibrated temperature value will be
displayed. If a temperature probe is connected, the current
measured temperature will be displayed.
3. "Or" (Over range) indicates the reading exceeds the maximum
measurement range.
"Ur" (Under range) indicates the reading is under the minimum
measurement range (see Section 7 Specifi cations).

3. CALIBRATION

3.1 pH Calibration

The meter is capable of calibrating up to 3 pH values using USA or NIST
(nSt) pH buff er standards or 2 pH values with Low Ionic (Pb) pH buff er
standard. All new calibration values will automatically override existing
data.
USA group
NIST group
Pb group
For the best results perform at least a 2-point calibration at room
temperature (25 °C) using standard buff ers. Begin with pH 7.00 (USA
group), pH 6.86 (NIST group) or pH 6.97 (Pb group).
For a 1-point calibration, the calibration should be performed with a pH
buff er value closest to the expected sample value being measured.
The meter has automatic buff er recognition that identifi es the correct pH
buff er values during the calibration. The meter will accept calibration
values that are within +/-1.0 pH units of the expected value, otherwise
the DISPLAY will fl ash "Er1" and the value will not be accepted. Press
CAL to abort the calibration and return to the measurement mode.
Always use new pH buff er solutions for calibration. Do not reuse
buff er solutions that may be contaminated and aff ect the calibration
and accuracy of the measurements. Promptly seal containers and store
solutions in a dark, dry, cool environment.
4.01, 7.00, 10.01
4.01, 6.86, 9.18
4.10, 6.97
10