• From Sara Lance at SPEC Inc.
• Materials needed:
  • Several regular cotton swab
  • Methanol

1. Wet a cotton swab completely with methanol. Gently wipe the entire optics window.
2. 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.
3. Repeat for all the optics 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.

1. Take the 2DS out of the PMS can and put it onto a probe cradle.
2. 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.
3. Carefully rotate the probe 180 degrees and clean all three sets of optics windows on that side of the probe.

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.

• 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.

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