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26
NOTE: Be sure
you can get a spark from the striker BEFORE you turn on the gas!
1.
Shut both the air supply opening and the
gas valve at the base of the burner.
2.
Open the gas valve by turning the screw
one complete revolution. Next, open
the air supply so
that the openings of the air vents on
the barrel of the burner are approximately one-quarter
exposed.
3.
Light the burner with the striker.
The spark is formed on the underside of the striker so this
side must be oriented towards the gas
stream. The flame should be large and yellow.
4.
Slowly open the air vents to increase
the air supply until the main part of the flame is colorless
and a small inside blue cone is visible.
5.
Reduce the gas supply by partly closing
the valve at the base of the burner until the flame is
about 10 cm high.
6.
Adjust the air supply until the inner
blue cone is about 3 cm high.
7.
Once you have finished using the flame,
immediately turn off the gas supply using
the control
valve on the bench top. NEVER leave
a Bunsen burner with an open flame unattended or
when it is not being used.
Sometimes the air-gas mixture begins to
burn before it reaches the top of the burner. If this
happens, the barrel will become very hot
and the flame will become green. The gas supply must
be shut off immediately and the burner
allowed to cool before relighting.
As indicated in the above illustration,
the hottest part of the flame is directly above the tip of the
inner blue cone.
