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FOUR-POINT CALIBRATION
• Remove the third standard cuvette.
• Place the cuvette for third calibration point:
• 750 FNU (NTU) calibration cuvette for NTU
ratio mode.
• 750 NTU formazin prepared standard for NTU
non‑ratio and FNU modes.
• 2000 NTU formazin prepared standard for FAU
mode.
Note: If necessary, press UP or DOWN key to edit each calibration point value to match the exact value
of the standard as measured with a reference turbidimeter.
• Close the lid and press “Read” functional key. The display will show the value blinking and the
light icon during measurement.
• The “Store...” message is displayed for FAU, FNU and NTU non‑ratio modes and the calibration is
saved. The instrument returns to the main screen.
• The fifth proposed calibration point, 2000 NTU for NTU Ratio mode, is displayed.
• At this moment it is possible to exit calibration
by pressing “End” functional key.
• If the calibration is terminated, the display will
briefly show “Store...” and the four point calibration
is saved. The instrument returns in the main screen.
FIFTH CALIBRATION POINT (NTU Ratio Turbidity only)
• Remove the fourth standard cuvette.
• Place the 2000 NTU calibration cuvette (or the
fifth prepared formazin standard) into the holder,
with the cuvette mark aligned to the sign on the
instrument top.
