HP 8168E User Manual page 239

Cleaning Metal Filters or Attenuator Gratings
This kind of device is extremely fragile. A misalignment of the grating leads to inaccurate
measurements. Never touch the surface of the metal lter or attenuator grating. Be very careful
when using or cleaning these devices. Do not use cotton-swabs or soft-tissues, as there is the
danger that you cannot remove the lint and that the device will be destroyed by becoming
mechanically distorted.
1. Use compressed air at a distance and with low pressure to remove any dust
Preferred
or lint.
Procedure
Do not use an ultrasonic bath as this can damage your device.
Procedure for
Stubborn Dirt
Use this procedure particularly when there is greasy dirt on the device:
1. Put the optical device into a bath of isopropyl alcohol, and wait at least 10
minutes.
2. Remove the uid using compressed air at some distance and with low
pressure.
If there are any streaks or drying stains on the surface, repeat the whole
cleaning procedure.
Cleaning Procedures E-13