Hanna Instruments HI 2214 - Manual (Page 9)

9
RELATIVE mV MEASUREMENTS
• Press RANGE until “rEL” message and “mV” tag are displayed for
one second. After one second the temperature will be displayed on
the secondary LCD and the “
mV” tag will blink.
The reading displayed by the instrument is equal to the difference
between the current mV input value and relative mV offset established in
the relative mV calibration.
TEMPERATURE MEASUREMENTS
Connect the HI 7662 temperature probe to the
appropriate socket and turn the instrument on.
Submerse the temperature probe into the sample
and allow the reading on the secondary LCD to stabilize.
ppppp H CALIBRATION H CALIBRATION H CALIBRATION H CALIBRATION H CALIBRATION
Calibrate the instrument frequently, especially if high accuracy is
required.
The instrument should be recalibrated:
• Whenever the pH electrode is replaced.
• At least once a week.
• After testing aggressive chemicals.
• If “
CAL” “INTV” tags are blinking during measurement.
Every time you calibrate the instrument use fresh buffers and perform an
electrode Cleaning Procedure (see page 38).
PREPARATION
Pour small quantities of the buffer solutions into clean beakers. If
possible, use plastic or glass beakers to minimize any EMC interferences.
For accurate calibration and to minimize cross-contamination, use two
beakers for each buffer solution. One for rinsing the electrode and one for
calibration.
If you are measuring in the acidic range, use pH 7.01 or 6.86 as first
buffer and pH 4.01 as second buffer. If you are measuring in the alkaline
range, use pH 7.01 or 6.86 as first buffer and pH 10.01 or 9.18 as
second buffer.