User Guide

26
• Mark the vial with a pencil on the
white band to place an orientation
sign. Use this sign to insert the test
vial always in the same position into
the holder.
• Place the vial into the holder and
push it completely down.
• Press ZERO and “SIP” will blink on the display.
• Wait for a few seconds and the
display will show “-0.0-”. Now the
meter is zeroed and ready for
measurement.
• Remove the vial.
• Remove the cap and add 4 drops of
HI 93764-0 Nessler Reagent.
• Replace the cap tightly and mix by
inverting the vial a couples of times.
This is the sample.
• Place the vial into the holder and
push it completely down. Ensure that
the vial orientation respect to the
holder is the same as the blank.
• Press TIMER and the display will show the countdown prior to the
measurement. Alternatively, wait for 3 minutes and 30 seconds
and press READ DIRECT. In both cases "SIP" will blink during
measurement.
Ammonia HR
55
COD HR
• Select the program number corresponding to Oxygen Demand,
Chemical HR (COD) on the secondary LCD by pressing PROGRAM
t and s.
• Place the blank vial into the holder
and push it completely down.
• Press ZERO and "SIP" will blink on the display.
• Wait for a few seconds and the
display will show “-0.0-”. Now the
meter is zeroed and ready for
measurement.
• Remove the blank vial.
• Place the sample vial into the holder
and push it completely down.
• Press READ DIRECT and "SIP" will blink during measurement.
• Multiply the reading on the Liquid Crystal Display
by 10 to
obtain the concentration in mg/L of oxygen demand.
INTERFERENCES
Interference may be caused by:
Chlorides (Cl
-
): above 20000 mg/L.
Samples with higher chloride concentration should be
diluted.