Hach Intellical MTC30101, Руководство пользователя, Страница: 7 / 16

1. Fill a 10 mL
burette with a
standard titrant
solution with a
normality that is
5-10 times that of
the sample.
2. Connect the
probe to the
meter.
3. Pipet a 50 mL
sample into a
150
‑
mL beaker.
Stir with a
magnetic stirrer
throughout the
titration.
4. Add titrant in
0.5 to 1 mL
increments.
Record the
potential after
each addition.
Near the end
point, when large
potential changes
are seen, add
increments of 0.1
to 0.2 mL.
Continue the
titration 3 to 4 mL
past the end point.
5. Plot the
electrode potential
versus volume of
added titrant and
fit a smooth curve
through the points.
The end point is
the point of
inflection (the
point of greatest
slope).
6. Calculate the
normality of the
sample, N
x
, in
equivalents per
liter:
N
x
= (V
t
x N
t
) / V
x
where:
N
t
= normality of
titrant (Eq/L)
V
t
= volume of
titrant at end point
(mL)
V
x
= Volume of
sample (mL)
Run Check Standard
The Run Check Standard feature validates the instrument performance between sample
measurements. Use the Run Check Standard feature for a periodic or a user-defined
interval measurements of a traceable standard solution. Set the criteria for check
standards from the MTC301 probe Settings menu.
Note: Access control must be set to off or a valid password must be used to change the Run Check
Standard options.
1. Push . The Full Access Options menu shows.
2. Select Run Check Standard.
Note: Select the correct probe if two probes are connected to the meter.
3. Use the standard solution shown on the display.
4. Rinse the probe with deionized water. Dry the probe with a no-lint cloth.
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