Total Station Setup
Overview
Total station setup is a fundamental procedure in modern surveying that establishes the instrument's position, orientation, and readiness for accurate measurements. A total station is an electronic surveying instrument that combines distance measurement, angle measurement, and data recording capabilities. Proper setup ensures measurement accuracy and efficient field operations.
Key Setup Components
1. Tripod Positioning
The first step involves selecting a stable, level location for the tripod. The tripod legs should be spread evenly, with the instrument positioned at approximately eye level for operator comfort. The tripod must be firmly planted in the ground with adequate weight distribution to prevent movement during measurements.
2. Instrument Mounting
The total station is carefully mounted to the tripod's center screw, ensuring a secure connection. The instrument must be centered directly over the survey point marker (nail, stake, or benchmark) using the optical plummet or laser plummet feature available on most modern units.
3. Leveling Procedures
Leveling involves two distinct operations. First, the circular bubble level is used to make coarse leveling adjustments by manipulating the tripod leg lengths. Second, the tubular level or electronic level sensor achieves fine leveling by adjusting the leveling screws on the instrument base. Proper leveling is critical because even minor deviations can introduce significant errors in angle measurements.
4. Orientation and Backsight
Once leveled, the total station must be oriented by establishing a known reference direction. This is accomplished by:
The orientation procedure establishes the baseline from which all subsequent angles are measured.
5. Focus and Adjustment
Proper optical focus is essential for accurate measurements. The eyepiece must be focused to the operator's vision, and the crosshair focus ring adjusted until the reticle appears sharp. Modern total stations include automatic focusing features that reduce operator error.
Quality Assurance
Centering Verification
After setup is complete, verify that the instrument remains centered over the survey point by checking the optical plummet again. Any deviation requires minor adjustment using the tripod's fine-positioning screws.
Test Measurements
Perform test measurements on known distances to verify instrument accuracy. Many surveyors measure distances to temporary points and compare results to establish a confidence baseline.
Environmental Considerations
Monitor environmental conditions affecting measurements:
Advanced Setup Features
Modern total stations include:
Common Setup Errors
Avoid these frequent mistakes:
Conclusion
Proper total station setup is the foundation of accurate surveying work. Taking time for careful positioning, leveling, and orientation prevents costly measurement errors and ensures reliable survey data for construction, mapping, and land development projects. Regular verification throughout the survey day maintains data integrity and professional standards.