Keysight 81618A/9A and Keysight 81620B/3B/4B/6B/8B Optical Heads User’s Guide 107Cleaning Information 5Alternative ProcedureFor these types of optical devices you can often use an ultrasonic bathwith isopropyl alcohol. Only use the ultrasonic bath if you are sure that itwon't cause any damage any part of the device.1 Put the device into the bath for at least three minutes.2 Blow away any remaining liquid with compressed air.If there are any streaks or drying stains on the surface, repeat the cleaningprocedure.How to clean metal filters or attenuator gratingsThis kind of device is extremely fragil e. A misalignment of the grating leadsto inaccurate measurements. Never touch the surface of the metal filter orattenuator grating. Be very careful when using or cleaning these devices.Do not use cotton swabs or soft tissues, as there is the danger that youcannot remove the lint and that the device will be destroyed by becomingmechanically distorted.Preferred ProcedureUse the following procedure on most occasions.1 Use compressed air at a distance and with low pressure to remove anydust or lint.Procedure for Stubborn DirtDo not use an ultrasonic bath as this can damage your device.1 Use this procedure when there is greasy dirt on the device:2 Put the optical device into a bath of isopropyl alcohol, and wait at least10 minutes.Remove the fluid using compressed air at some distance and with lowpressure. If there are any streaks or dr ying stains on the surface, repeat thewhole cleaning procedure.
