How to use IPA rag to remove dust from precision instruments

1. Pre-Operation Preparation: Safety & Compatibility Checks

• Instrument & Workspace Prep:
  1. Power down the instrument and disconnect it from the power source (critical for electronics-containing tools, e.g., HPLC detectors) to eliminate 触电 and ESD risks.
  2. Move the instrument to a clean, well-ventilated area (or use a fume hood for large instruments) to avoid airborne dust recontamination during cleaning. Cover non-cleaning areas (e.g., display screens, control panels) with a lint-free dry cloth to protect them from accidental IPA contact.
• IPA Wipe Selection:
  1. Choose 99% electronic-grade IPA wipes for non-optical surfaces (e.g., metal housings, sensor enclosures)—high purity avoids residue that could clog components. For optical surfaces (e.g., microscope objectives, laser lenses), use 70% lens-grade IPA wipes (water content reduces evaporation rate, preventing streaks) or deionized water-based IPA wipes (to protect anti-reflective [AR] coatings).
  2. Ensure wipes are lint-free (continuous-filament polyester/microfiber)—staple-fiber wipes shed fibers that worsen dust contamination. Avoid wipes with added fragrances or preservatives (they leave sticky residues).
• Compatibility Test:
  1. Test the IPA wipe on an inconspicuous area of the instrument (e.g., the bottom of the housing) before full use. Wait 5 minutes to check for discoloration, swelling (for plastic parts), or coating damage (for painted/AR-coated surfaces).

2. Step 1: Remove Loose Dust First (Critical for Scratch Prevention)

1. Use a static-neutralized bulb blower (not compressed air, which forces dust into crevices) to gently blow loose dust from large surfaces (e.g., instrument tops, lens exteriors) and hard-to-reach areas (e.g., button gaps, sensor ports). Hold the blower 10–15cm away from the surface to avoid excessive pressure.
2. For fine dust in narrow gaps (e.g., between control knobs), use a clean, dry, lint-free swab (attached to a wooden or plastic handle—avoid metal, which can scratch) to lightly dab the area. Discard the swab after use to prevent cross-contamination.

3. Step 2: Targeted Dust & Residue Removal with IPA Wipes

• For Flat, Non-Optical Surfaces (e.g., Metal Housings, Sensor Trays):
  1. Remove one IPA wipe from its sealed packaging (do not leave wipes exposed—IPA evaporates quickly, reducing efficacy). Fold the wipe into a 4-layer pad to create a firm, absorbent surface and avoid direct finger contact with the instrument.
  2. Wipe the surface in slow, single linear strokes (horizontal or vertical)—never circular motions (which spread dust and residue). Apply light pressure (<0.5 psi) to avoid pressing dust into the surface or damaging delicate parts (e.g., plastic latches).
  3. Use a fresh section of the wipe for each stroke (unfold the pad to expose clean fibers) to prevent re-depositing dust.
• For Optical Surfaces (e.g., Lenses, Detector Windows):
  1. Fold the IPA wipe into a small, soft pad (2–3cm wide) to match the lens size—avoid using large wipes that contact non-optical areas (e.g., lens barrels, which may have plastic components sensitive to IPA).
  2. Gently dab the lens surface (not wipe) to lift dust and residues—dabbing minimizes friction and protects AR coatings. For stubborn spots (e.g., dried oil), hold the wipe against the spot for 2–3 seconds to let IPA dissolve it, then dab once.
  3. Immediately follow with a dry, lint-free optical wipe to blot excess IPA—moisture can damage lens coatings or cause streaks as IPA evaporates.
• For Small Components (e.g., Connector Ports, Micro-Sensor Tips):
  1. Tear the IPA wipe into a thin strip (1cm wide) and wrap it around the tip of a clean pair of tweezers (with plastic tips to avoid scratching).
  2. Gently insert the wipe-wrapped tweezers into connector ports or around sensor tips to remove dust—do not force the tweezers (risk of bending pins or damaging sensors).

4. Step 3: Post-Clean Inspection & Protection

1. Inspect the instrument under bright, angled light (or use a 10–20x magnifying glass for optical surfaces) to check for remaining dust, fiber debris, or streaks. If spots remain, repeat Step 3 with a fresh IPA wipe (do not reuse wipes).
2. For electronics-containing instruments (e.g., mass spectrometers), wait 10–15 minutes to ensure all IPA has evaporated before reconnecting power—moisture can cause short circuits.
3. Cover the cleaned instrument with a lint-free, breathable dust cover (avoid plastic covers, which trap moisture) to prevent dust accumulation until next use.

Critical Prohibitions to Avoid Damage

• Do NOT use IPA wipes on uncoated aluminum (causes discoloration), soft plastics (e.g., PVC—IPA causes cracking), or exposed circuit boards (unless using 70% IPA and the instrument is fully powered down).
• Do NOT scrub or apply heavy pressure—this scratches surfaces and embeds dust into delicate components.
• Do NOT reuse IPA wipes—used wipes trap dust and residues, spreading contamination.