19
■
Maintenance
■
Checking the heater/sensor
This procedure, if followed daily, will materially
add to tip life.
a. Set the temperature to 250°C (482°F).
b. When the temperature stabilizes, clean the tip
and check the condition of the tip. If the tip is
badly worn or deformed, replace it.
c. If the solder plated part of the tip is covered
with black oxide, apply fresh solder, containing
flux, and clean the tip again. Repeat until all
the oxide is removed, then coat the tip with
fresh solder.
CAUTION
NEVER file the tip to remove oxides!
d. Turn the power OFF and remove the tip, using
the heat resistant pad. Set the tip aside to
cool.
e. Remaining oxides, such as the yellow
discoloration on the tip shaft, are not harmful
but, can be removed with isopropyl alcohol.
Measure the resistance between
this pointand the heater/sensor.
Measure the resistance at room temperature
(15 to 25°C ; 59 to 77°F). The normal range is
8
Ω
±10%. If the resistance is outside this range,
replace the nozzle assembly.
