Hach-Lange 2100 N Laboratory Turbidimeter User Manual - Manual (Page 16)

Measure the Gelex stray light standard
Measure the Gelex stray light standard when the instrument is first received. Record the value on the Gelex vial with a permanent marker one time.
1. Clean the stray light
standard with a soft,
lint-free cloth to remove
water spots and
fingerprints. 2. Apply a small bead
of silicone oil from the
top to the bottom of the
vial. 3. Use the oiling cloth
to apply the oil equally
to the surface of the
vial. Remove the
excess oil. Make sure
that the vial is almost
dry. 4. Push RANGE to
select automatic
ranging.
The Auto Range light
turns on. 5. Push SIGNAL AVG
to turn signal averaging
off.
The SIGNAL AVG light
turns off. 6. Push UNITS/Exit to
select the NTU
measurement mode.
The NTU light turns on.
7. Push RATIO to turn
Ratio mode on. 8. Put the stray light
standard in the sample
cell holder with the
triangle on the vial
aligned with the
reference mark on the
sample cell holder.
Close the cover. 9. Read the value
when stable. Remove
the vial from the
instrument. 10. Record the value
on the white diamond
space on the vial using
a permanent marker.
14 English