Hach-Lange 2100 N Laboratory Turbidimeter User Manual - Manual (Page 14)

• All nephelometric (turbidity units of measure) calibrations are done at
the same time.
• Ratio-on and Ratio-off calibration data is measured and recorded at
the same time.
• Clean the USEPA filter assembly before doing a primary calibration,
or at least every 3 months (which is the USEPA-recommended
primary calibration interval).
StablCal calibration procedure
1. Remove the filter
assembly. Refer to
Change the filter
assembly
on page 36.
2. Clean the lens of the
USEPA filter assembly.
Refer to
Clean the filter
assembly on page 36.
3. Hold the tab of the
USEPA filter assembly
so that the arrows point
toward the front of the
instrument. Push the
filter assembly fully in
the housing. 4. Push CAL.
The S0 light turns on.
The NTU value of the
dilution water used in
the last calibration is
shown on the display. 5. Get the < 0.1 NTU
vial. Clean the vial with
a soft, lint-free cloth to
remove water spots and
fingerprints. Do not
invert the vial. 6. Apply a small bead
of silicone oil from the
top to the bottom of the
vial.
12 English