In
electronic engineering a getter is a substance that removes
unwanted gasses. Getters is usually divided in to two
groups;
evaporative and non-evaporative.
Evaporative getters is used in for example
light bulbs,
where they are
sputtered on the
filament. The first
time the bulb is used the getter
vaporizes and
starts to
flow around in the bulb. If the getter
intersects oxygen, the two will bind in to a less
reactive material. If the oxygen is allowed to be
in the bulb, it will
oxidize the
filament and
reduce the
lifetime of the bulb. This getter type
is usually a
phosphor compound
Non-evaporative getter is used in
vacuum tubes and
for example the
field emission display. It consists
of for example a
zirconium-
aluminium or
zirconium-
Iron alloy. This getter will not evaporate
but will
absorb gas
atoms that comes near it.
This getters has a high reactivity to normal air molecules
like
CO,
O2,
H2,
CO2 and will also remove water(
H2O).