User Guide

10
In this case, switch back
to "STB" position, place
the protective cap and
wait for a few hours for
complete polarization be-
fore proceeding.
• Using a small screwdriver, turn the Zero Cali-
bration screw until the display reads zero.
• If the zero point is
passed, "1" will appear
on the display. If you can-
not get zero reading the probe is probably
defective, in which case you should check
the membrane, electrode and electrolyte
solution (see below).
Rinse the probe thoroughly with normal tap water
after the zero calibration has been completed.
SLOPE CALIBRATION:
In order to perform a highly
accurate calibration, take a
B.O.D. bottle and then fill with
water to a depth of 1 or 2 cm
(½ or ¾"), then seal the bottle
with the probe inside.
If this calibration is to be car-
ried out with the bottle opened
to air rather than according to
the conditions described
above, the margin of error is
approximately 0.1 ppm.
• Switch the instrument to
"°C", wait for readings to
stabilize and then note the
temperature of the water.
OFF
O
2
STB °C
OFF
O
2
STB °C
SLOPE
ZERO
°C