• All nephelometric (turbidity units of measure) calibrations are done at
the same time.
• The 4000-NTU standard does not have to be measured during
calibration if FNUs will be measured. Push CAL after the 1000 NTU
standard is measured to complete the calibration procedure.
StablCal calibration procedure
1. Push CAL.
2. Get the < 0.1 NTU
vial. Clean the vial with
The S0 light turns on.
a soft, lint-free cloth to
The NTU value of the
remove water spots and
dilution water used in
fingerprints. Do not
the last calibration is
invert the vial.
shown on the display.
10 English
• The FNU values of StablCal standards and formazin standards are
calculated using the conversion factors of 1 FNU = 1 NTU.
3. Apply a small bead
4. Use the oiling cloth
of silicone oil from the
to apply the oil equally
top to the bottom of the
to the surface of the
vial.
vial. Remove the
excess oil. Make sure
that the vial is almost
dry.
5. Put the vial in the
6. Push ENTER.
sample cell holder with
The instrument display
the triangle on the vial
counts down, then
aligned with the
measures the standard.
reference mark on the
The next expected
sample cell holder.
standard (e.g., 20.00) is
Close the cover.
shown. The S1 light
turns on.