27
Fig. 7-4
Step five: replace the required light source
1
）
Tungsten lamp replacement
Turn the W lamp flake right slightly.
Remove the old tungsten lamp by wearing a pair of cotton gloves.
Insert a new tungsten lamp into the base
（
12V20W
）
, turn the flake to its original position.
2
）
Deuterium lamp replacement
Loosen the two screws from the D2 lamp holder;
Pull out the coupler plug, and take off the old deuterium lamp.
Mount the new lamp by wearing a pair of cotton gloves.
Screw up the two crews.
Don’t touch the light source cover if the instrument has worked for a while and the cover is
hot.
The ultraviolet radiation emitted by the deuterium lamp and the strong light emitted by the
tungsten lamp will harm your eyes. Please do not light the lamps when adjusting the instrument.
Do not touch the reflective surface of the light source mirror during the lamp changing
procedure; otherwise, it will adversely affect the performance of the instrument, even cause the
instrument inoperative.
Please wear cotton gloves when you change lamps to avoid adversely affect the
performance of the instrument.