7
• Pour about 10-20 mL of the sample in a clean beaker and add
the same quantity of
HI 4010-00
(TISAB) solution to the beaker.
Mix the solution for a few minutes.
• Rinse the electrodes with deionized wa-
ter and dry them attentively with a
non-abrasive cloth.
• Immerse the fluoride and the reference
electrode as well as the temperature
probe to a depth of at least 1 cm (½”)
in the prepared sample.
Make sure that the electrodes are not touching the bottom of the
beaker. Position the temperature probe close to the tip of the
other electrodes.
• Wait until the display stabilizes (about
10-15 minutes). The fluoride ion con-
centration and the temperature will
be displayed on the upper and lower
displays, respectively.
Notes
: •
The reading is automatic temperature compensated in a -
5.0 to 55.0 °C temperature range. The ATC tag appears
on the LCD to indicate this. Outside this interval the meter
will not compensate for the temperature variance, and the
ATC tag will blink. The instrument will display the reading
taking into account a 25 °C temperature value.
•
If the temperature probe is not connected, the meter will
not compensate for the temperature variance. In this
case, accurate fluoride measurements are only possible if
the temperature of the sample and the calibration
solutions are close (no more than ±3°C apart).
•
It is recommended to mix the sample during the measure-
ment, using a magnetic stirrer set at around 100 rpm.
MAGNETIC STIRRER
HI 190M
POWER
SPEED
ON
OFF
MAX