Stablcal calibration procedure – Hach-Lange 2100 AN Laboratory Turbidimeter Basic User Manual User Manual
Page 12
• 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.
• The 7500-NTU standard does not have to be measured during
calibration if turbidity less than 4000 NTU will be measured. Push
CAL/Zero after the 4000 NTU standard is measured to complete the
calibration procedure.
• 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
2. Clean the lens of the
USEPA filter assembly.
Refer to
on page 17.
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/Zero.
The CAL/Zero light
turns on, and the mode
display shows "00". The
NTU value of the
dilution water that was
used in the previous
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