====== 2DS Cleaning ======

===== Exterior Optics Windows =====
  * From Sara Lance at SPEC Inc.
  * Materials needed: 
     * Several regular cotton swab
     * Methanol

  - Wet a cotton swab completely with methanol.  Gently wipe the entire optics window.
  - Partially wet a second cotton swab with methanol.  Gently wipe the entire optics window and dab away any excess methanol remaining on the optics window.  
  - Repeat for all the optics windows.

===== Interior Optics Mirrors and Windows =====
  * From Sara Lance at SPEC Inc.
  * This can be done to help reduce noise on the 2DS if the noise is not due to dirty exterior optic windows.
  * Materials Needed: A can of compressed air.
  * Desiccant Packs, 5 g, 2.25 by 1.0 inch.

  - Take the 2DS out of the PMS can and put it onto a probe cradle.
  - Gently spray compressed air over all of the interior mirrors and windows located in the probe body.  There are three sets of mirrors and windows: 
     * Windows located where the probe arms meet the probe body.
     * Mirrors located above the photodiode array.
     * Mirrors located near the middle vertical support plate.
  - Carefully rotate the probe 180 degrees and clean all three sets of optics windows on that side of the probe.

{{:atmos:citation:instruments:2ds:2ds_internal_optics_cleaning.png?800|}}

UND graduate student Andrea Neumann cleaning the internal 2DS optics using a can of compressed air.  The green arrows denote the approximate locations of the three sets of internal optics.

===== 2DS Interior Desiccant =====
  * To help remove residual water vapor within the 2DS can, desiccant packets are affixed to the interior probe braces.
  * The desiccant packets are attached using cable ties and should be marked with the date of installation.
  * The cable ties should be tight enough to ensure the desiccant packet does not slide around, but not tight enough to cause the desiccant packet to break open.
  * The packets should be changed on a regular basis, once every week or two when on field projects.

{{:atmos:citation:instruments:2ds:p1060149.jpg?800|}}

An example of a desiccant packet affixed to an interior probe brace.