Instruction Manual

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4 METER CALIBRATION
4.1 Preparation for Calibration
a) Calibration Point
The instrument has 5 calibration points: 0 NTU, 20 NTU, 100 NTU, 400 NTU, and 800 NTU.
Among them, 0 NTU point uses AMCO 0.0 NTU calibration solution or laboratory distilled water,
and the remaining 4 calibration points use AMCO polymer solutions. Note that the cap of the 0.0
NTU solution vial can be unscrewed. After the solution is invalidated, users can replace the 0.0
NTU calibration solution or use fresh laboratory distilled water. The AMCO 0.0 NTU calibration
solution refill can be purchased from the supplier; For the remaining 4 calibration solutions, their
vial caps cannot be opened. Simply dispose the solutions after they are expired and buy new
ones from your supplier to replace. See the detail in Section 6 Replacement Parts.
b) Replace zero turbidity solution
⚫ Open the vial cap, pour out the original solution, add 1/2 distilled water, screw on the cap and
shake the vial to rinse it off and pour out the water. Repeat it 3 times. Shake off the distilled
water in the vial. Pour in new AMCO 0.0 NTU calibration solution or fresh laboratory distilled
water and close the vial cap.
⚫ AMCO 0.0 NTU calibration solution has 6 to 12 months of shelf-life, distilled water is only valid
for a couple of days. AMCO 0.0 NTU solution is provided in the default kit. For purchase
details, please refer to Section 6 Replacement Parts.
c) Clean vial surface
Apply a small drop of silicone oil on the surface of the vial and wipe it off with a lint-free cloth to
evenly distribute the silicone oil on the surface in order to cover smudges and scratches, which
helps light scattering. But please pay attention to the following points:
① The silicone oil applied should not be too much. After wiping with lint-free cloth, please wipe
with filter paper or high-quality tissue paper to clean off. Excessive residual silicone oil on the
vial surface will affect the measurement accuracy.
② It's not necessary to use silicone oil for each calibration and measurement. Apply silicone oil
every several days or once a week. In between, just clean the surface with filter paper or
high-quality tissue paper.
③ Clean the calibration vial and sample vial together and keep the steps and actions consistent
to achieve same degree of cleanliness.
④ Stability of calibration solutions
⑤ The U.S EPA approved AMCO polymer standard calibration solution is very uniform and
stable. It does not precipitate, drift or condense. Generally, it can be used directly without
shaking or flipping the vial (to make the solution even). For AMCO polymer calibration