2.3 Equipment Care, Cleaning, Storage, and Transport Safety
Key Takeaways
- Abrasive dust and grit must be blown off optical lenses with a bulb blower brush before wiping to prevent dragging quartz particles across anti-reflective glass coatings.
- Lens cleaning fluid must always be applied to lens tissue or microfiber cloth, never directly onto glass elements where it can seep into lens barrels.
- Instruments exposed to rain must never be left locked in sealed cases overnight; they must be removed, wiped dry, and allowed to air-dry at room temperature to prevent mold and corrosion.
- Total stations must be transported in factory hard cases secured flat in vehicles, and dismounted from tripods when carried between setup points on site.
- Tribrach footscrew threads should be cleaned with a toothbrush and lubricated only with dry silicone or graphite powder—never heavy grease.
2.3 Equipment Care, Cleaning, Storage, and Transport Safety
Surveying equipment represents a major capital investment. Modern total stations, digital levels, optical tribrachs, and GNSS receivers contain sensitive glass optics, electromagnetic angle encoders, laser diodes, and delicate circuit boards. Inadequate field care, improper lens cleaning, or rough transport degrades measurement accuracy, voids manufacturer calibrations, and leads to expensive repair downtime. This section covers daily pre-operation inspections, optical lens cleaning, moisture prevention, vehicle transport safety, and tribrach field maintenance.
Daily Pre-Operational Inspection Protocol
Before deploying surveying equipment to a remote jobsite, technicians must perform a systematic five-point inspection:
- Mechanical & Hardware Check: Inspect tripod leg clamps, shoe rivets, top plate screws, and tribrach footscrews. Verify that screws turn smoothly without binding, slipping, or excessive play.
- Optical & Glass Inspection: Check objective lenses, eyepieces, optical plummet windows, and prism faces for dust, mud, fingerprints, or scratched anti-reflective coatings.
- Electronic & Power Check: Verify battery latches, rubber weather seals, pin connectors, memory card doors, and screen display backlights. Ensure batteries are fully charged.
- Tribrach & Plummet Calibration: Confirm that the optical plummet reticle and circular bubble are aligned and free of mechanical looseness.
- Case & Accessories Check: Inspect carrying case latches, shoulder straps, rain covers, and internal custom-molded foam inserts.
Optical Lens Cleaning Procedures
The optical glass lenses of total stations and levels are treated with ultra-thin anti-reflective metal chemical coatings. Improper cleaning techniques scratch glass surfaces and strip these optical coatings, permanently degrading image clarity and distance measurement signal return strength (EDM signal loss).
[ LOOSE DIRT / SAND ] -----> Blow away with Bulb Blower Brush (Step 1)
|
v
[ UNBONDED DUST ] ---------> Brush gently with Camel-Hair Brush (Step 2)
|
v
[ OIL / FINGERPRINTS ] ----> Wipe outward in circles with Lens Fluid on Tissue (Step 3)
The Golden Rule of Optical Cleaning
NEVER wipe dry dust, grit, or sand across an optical lens surface! Dry dust contains quartz silica particles (hardness 7 on Mohs scale), which will deeply gouge optical glass when dragged by a cloth.
Step-by-Step Standard Lens Cleaning SOP
- Blow Away Abrasive Grit: Use a clean rubber bulb blower brush (or clean, dry compressed air held upright) to blow away all loose surface dust, sand, and grit particles.
- Brush Lightly: Gently sweep remaining unbonded particles off the lens using a soft camel-hair brush.
- Apply Cleaning Liquid to Tissue (NOT Lens): Apply a few drops of pure photographic lens cleaning fluid (or $99\%$ pure isopropyl alcohol) directly onto a fresh sheet of lint-free optical lens tissue or clean microfiber cloth.
[!CAUTION] NEVER apply lens cleaning fluid directly onto the glass lens element! Fluid sprayed directly on glass seeps past retaining rings into internal lens barrels, causing internal fogging, electronic short-circuits, and cement separation between lens doublets.
- Wipe Outward Circularly: Gently wipe the lens surface starting at the center and moving outward in expanding concentric circles toward the edge.
- Single-Use Tissue Disposal: Discard used lens tissues immediately. Never reuse a dirty tissue across multiple lenses, as trapped particles will scratch subsequent glass elements.
Forbidden Cleaning Substances
- Household Glass Cleaners (Windex, Ammonia): Chemical solvents strip anti-reflective lens coatings and erode rubber seals.
- Acetone / Paint Thinners: Dissolve internal plastic barrels, sealants, and lens cements.
- Paper Towels, Facial Tissues, Shirt Sleeves: Contain coarse wood fibers that scratch delicate optical glass.
Moisture Prevention and Storage Protocols
Surveying instruments feature Ingress Protection (IP) ratings (e.g., $\text{IP65}$ or $\text{IP66}$), certifying dust-tight performance and resistance to water jets. However, weatherproofing does NOT protect equipment against trapped internal moisture when stored improperly.
| Environmental State | Field Condition | Immediate Corrective Protocol | Long-Term Storage Standard |
|---|---|---|---|
| Rain / High Humidity Exposure | Instrument used during rain or heavy fog | Wipe exterior dry before putting in case for vehicle transit. | Unpack immediately at office. Leave case open to air-dry overnight at room temperature. |
| Cold-to-Warm Transition | Moving instrument from sub-zero winter air into heated office | Internal glass condensation fogging. | Keep instrument inside closed carrying case for $1\text{ to }2\text{ hours}$ to allow gradual temperature equalization. |
| Hot Vehicle Trunk | Stored in closed trunk in direct summer heat ($>140\text{°F}$) | Thermal breakdown of optical lubricants and battery degradation. | Transport in climate-controlled vehicle cab; store in dedicated equipment room ($60-75\text{°F}$). |
[!IMPORTANT] The Wet Case Storage Trap: Leaving a wet surveying instrument locked inside a sealed plastic carrying case overnight creates a high-humidity greenhouse effect ($100\%\text{ RH}$). Trapped moisture penetrates internal seals, rusting internal gears, corroding circuit boards, and promoting destructive mold/fungus growth inside optical barrels. Always open wet cases and air-dry equipment completely!
Equipment Transport Safety
Vehicle Transport Rules
- Always Use Factory Hard Cases: Never transport total stations or levels loose on vehicle seats or floorboards. Secure instruments inside their factory hard cases with internal foam inserts.
- Secure Case Position: Place instrument cases flat on vehicle seats or padded floor mats. Fasten seatbelts or cargo straps across cases to prevent sliding, flipping, or impact during sudden braking.
- Vibration Mitigation: Long-distance driving over unpaved washboard roads transmits high-frequency vibrations that loosen internal collimation screws and optical prisms. Place cases on cushioned foam pads.
Field Transport Rules (Short Distances On-Site)
- Total Station Field Transport: Always dismount total stations from the tribrach and carry them by their built-in top handle in their cased transport box (or approved padded backpack harness) when moving between setup stations.
[!WARNING] Carrying Total Stations Over the Shoulder: Shoulder-carrying a total station attached to a tripod while walking across rough terrain is strictly prohibited. A tripped foot, loose tribrach clamp, or failing tripod leg lock will cause catastrophic destruction of the instrument.
- Automatic Level Transport: Over short, flat distances on open ground, an automatic level may remain mounted on a tripod provided it is held vertically in front of the operator's body with both hands securing the tripod head.
Tribrach Maintenance and Field Calibration
The tribrach provides the mechanical interface between the tripod and instrument housing the optical plummet and leveling head.
[ Instrument / Total Station Base ]
|
+---------------+---------------+
| Tribrach Top Plate |
+---------------+---------------+
/ | \
Footscrew Footscrew Footscrew
(A) (B) (C)
+---------------+---------------+
| Tribrach Base Plate |
+---------------+---------------+
|
[ 5/8" x 11 Centering Screw ]
Tribrach Care Standards
- Cleaning Screws: Keep leveling footscrew threads free of sand, mud, and cement dust. Clean threads using a soft toothbrush. Apply dry silicone spray or micro-fine graphite powder if specified by the manufacturer—never apply heavy grease, which attracts abrasive dirt.
- Testing Tribrach Optical Plummet Calibration:
- Mount the tribrach on a tripod over a paper target mark on a smooth floor.
- Level the tribrach circular bubble carefully. Mark the optical plummet crosshair position on the target paper.
- Rotate the tribrach $180\text{ degrees}$ on its base plate (using an adjusting cylinder or tribrach adapter).
- If the plummet reticle moves off the mark, adjust the optical plummet capstan screws to move the reticle back halfway to the mark. Re-level and verify.
Common Field Traps and Exam Pitfalls
[!WARNING] Exam Trap 1 — Spraying Cleaner Directly on Optics: Liquid cleaner seeps behind objective lens retaining rings into the telescope barrel, causing permanent internal fogging and delamination of optical adhesives.
[!WARNING] Exam Trap 2 — Shoulder-Carrying Mounted Total Stations: Carrying a $30,000 total station over one's shoulder on a tripod across brush or uneven ground is a primary cause of catastrophic equipment loss and severe structural damage.
What is the mandatory first step when cleaning dust and abrasive grit off a total station optical lens?
After operating a total station in heavy rain, what procedure MUST be followed upon returning to the field office?
Why must optical lens cleaning fluid be applied to lens tissue rather than sprayed directly onto the telescope glass element?
What is the proper method for transporting a total station between survey project sites in a field vehicle?