USER MANUAL
MI 106
pH/mV/Temperature
Portable Meter
GENERAL OPERATION
• The meter is supplied
complete
with a 9V
battery.
Remove the
battery compartment
cover on the back of the
meter and install the
battery while paying
attention to its polarity.
• Connect the
MA923D/1
probe to the
meter.
• Turn the instrument
on by
pressing the
ON/OFF key. At start-up,
the LCD
shows the percentage of the remaining
battery life for a few seconds, and then
the current measurement.
• Always remove the electrode
protective cap
before taking any
measurement. If the electrode has been
left dry, soak the tip (bottom 2.5 cm) in
M10000
rinse solution for a few minutes.
•
The temperature reading can be
displayed in °C or °F unit; to select the
desired scale, press and hold the
“ON/OFF” key until “TEMP” and the
current temperature unit are displayed
on the secondary LCD. Use the “SET”
button to select the unit and then press
the “ON/OFF” key a couple of times to
return to normal mode.
• To activate the HOLD function, keep
pressed the “HOLD” key. The measured
value will be frozen on the display and
the “HOLD” message appear on the
secondary LCD.
• After measurements, switch the
meter off by pressing the “ON/OFF” key.
The “OFF” message appears on the
LCD; release the button.
•
After use, replace the electrode
protective cap with a few drops of
storage solution.
TAKING pH MEASUREMENTS
• Select the “pH” mode with the “SET ”
key.
• Immerse the tip (2.5 cm) of the probe
in the sample and stir gently.
• Read the pH value when the clock
symbol stops blinking.
Note:
Before taking any measurement,
make sure that the meter has been
calibrated (the “CAL” tag is displayed on
the left lower corner of the LCD).
pH CALIBRATION PROCEDURE
It is recommended to recalibrate the
meter at least once every three weeks.
A) Preparation, Buffer solutions:
1.
pH 7.01
/
6.86 (MA9007 / MA9006)
2.
pH 4.01
(
MA9004
) for acidic
calibration
(pH < 7) or
pH 10.01 / 9.18
(
MA9010 /
MA9009
) for alkaline range (pH > 7).
Use two beakers for each buffer solution:
one beaker for rinsing the probe, the
other for calibration. In this way the cross
contamination between solutions is
minimized.
B) Procedure:
• Select the “pH” mode with the “SET ”
key.
• Select the calibration buffer set:
press and hold the “ON/OFF” key until
the LCD shows “TEMP”. Press again this
key and the “BUFF” message will
appear; then select the desired buffer set
with the “SET” key: “7.01 pH BUFF” (for
standard solutions: pH 4.01, 7.01, 10.01)
or “6.86 pH BUFF” (for NIST solutions:
pH
4.01, 6.86, 9.18). Press the
“ON/OFF” key again to exit.
• Remove the protective cap, then
immerse the probe in the first buffer (pH
7.01 or 6.86).
• Press and hold the “ON/OFF” key
until “CAL” is displayed on the lower
LCD.
• Release the button
and the message “7.01
pH USE” (or “6.86 pH
USE” for NIST buffer set)
will be displayed.
• The meter automatically recognizes
the buffer value: if a valid buffer is
detected, then its value is displayed on
the LCD together with
the “REC” message,
and the first calibration
point is accepted.
• The meter will then
require
the second
buffer by showing the
“pH 4.01 USE”
message.
Immerse the probe in the second buffer
solution (pH 4.01 or 10.01 or 9.18). If a
valid buffer is recognized, the meter
completes the calibration procedure,
shows the “OK 2” message for a few
seconds, then returns to the normal
mode.
Notes:
• If no valid buffer is
detected, the LCD will
show the “WRNG”
message.
• For exiting the calibration after the
first point is accepted, press the
