Diagnosis
Organic buildup on the smooth sensor window blocks the infrared and green light emission, degrading signal accuracy.
How to Fix It
Power OFF the sock. Use a lint-free microfiber cloth slightly dampened with distilled water. Gently wipe the smooth, slightly raised sensor window on the inside of the sock. Do not use any liquid directly on the sock. For the fabric exterior, spot clean with a cloth dampened with a mild soap solution. Never submerge the sock. Allow all parts to air dry completely for a minimum of 2 hours before reassembly and use.
If That Didn't Work
For persistent residue, use a cotton swab dipped in 70% isopropyl alcohol. Apply only to the hard plastic sensor window. Wipe gently in a circular motion. Immediately dry with a separate clean, dry part of the microfiber cloth. Do not let alcohol seep into the seams or fabric. Do not use bleach, hydrogen peroxide, or abrasive cleaners.
Heads Up
The sensor window is made of optical-grade polycarbonate. Scratching it will permanently ruin readings. Never use paper towels, tissues, or abrasive cloths. The fabric band is not machine washable. The removable footie is machine washable on a gentle, cold cycle—but remove it from the sock's core module first. The core module must never contact water.