6. Depress the ignition switch and hold down. Watch the FLM indicator in the
display
window. When this indicator is illuminated the flame is a light and the ignition switch
can
be released. If the FLM indicator does not light within approximately 20
seconds,
release the switch and open the fuel valve one additional turn. Allow the gas to disperse
before
continuing. Depress the ignition switch for a further 20 seconds. This process may
be
repeated until successful ignition occurs. If the fuel valve has to be opened more than
5
turns more than recommended above, refer to Section
7.5.
7. Set the filter select control to the desired
position.
8. Aspirate deionised water and set the readout to zero by adjusting the blank
control.
9. Aspirate a standard solution of slightly higher concentration than expected in
the
samples to be tested. Adjust the fine and coarse control until a positive reading
is
obtained. This is a nominal value to be used in optimising flame
conditions.
10. Adjust the fuel valve in a clockwise direction until a peak reading is
obtained.
NOTE: There is a time delay between adjusting the flow of fuel and
seeing
the
effect of the adjustment. A pause of a few seconds is
therefore
necessary
between making every fine
adjustment.
The optimum flame conditions are different for Na and K
and
retuning is necessary when switching between
elements.
11. For optimum performance the instrument should be allowed 15 minutes to
warm-up.
During this warm-up period a blank deionised water sample should be aspirated.
It
should be noted that results, adequate for most purposes, can be obtained from
switch
on, although standardisation settings will need frequent checking during the
warm-up
period.
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