12.16. Common Field Problems and Troubleshooting

Problem: No distance reading
Likely Cause: Prism not aligned or wrong constant and settings
Solution: Recheck prism position

This chunk addresses a common issue encountered during Total Station surveys where the instrument fails to provide a distance reading. The likely causes include misalignment of the prism or incorrect settings related to the prism constants. To resolve this issue, surveyors should carefully check and adjust the position of the prism to ensure it is properly aligned with the Total Station.

Imagine trying to take a picture with a camera but not having the lens pointed at the subject. Just like you would need to adjust the camera until it is focused correctly on the object, you need to ensure that the prism and the Total Station are correctly aligned to capture accurate distance measurements.

Problem: Angle errors
Likely Cause: Instrument not leveled
Solution: Re-level and re-center the instrument

In Total Station surveying, angle errors can occur when the instrument is not properly leveled. When the Total Station is uneven, it affects the accuracy of the angle measurements. To fix this issue, surveyors must re-level the instrument using its leveling screws or bubble levels to ensure it is flat and centered over the survey station before making further measurements.

Consider trying to measure a piece of furniture for a new room without ensuring that the measuring tape is flat on the ground. If you're measuring diagonally or at an angle, the measurement will be inaccurate. Leveling the Total Station is just like ensuring your measuring tape is straight and flat to get the right dimensions.

Problem: Inaccurate coordinates
Likely Cause: Wrong backsight or station input
Solution: Re-input station and orientation data

Inaccurate coordinates can arise if there are errors in inputting backsight or station data, which are crucial for the calculations performed by the Total Station. A backsight is a reference point used to calibrate measurements, and incorrect data will lead to erroneous coordinate outputs. The solution involves checking the inputs and inputting the correct backsight and station data again to ensure accurate coordinate calculations.

Think of it like setting the location in a navigation app. If you mistype your destination, the app will lead you to the wrong place. Similarly, entering the correct coordinates and reference points into a Total Station is essential for getting accurate results, just like having the right destination in your navigation system helps you reach your correct location.

Problem: Reflectorless mode fails
Likely Cause: Surface too absorbent or angled target surface
Solution: Use prism or re-orient angled target surface

When using the reflectorless mode on a Total Station, surveyors may encounter issues if the target surface is too absorbent, meaning it does not reflect the laser signal back effectively. Additionally, angled surfaces can also disrupt the accuracy of the reflected signal. To resolve this issue, surveyors can switch to using a prism, which is designed to reflect the signal accurately, or adjust the angle of the target surface to improve the reflectivity.

Imagine trying to shine a flashlight on a wall painted in a dark, absorbent color versus a shiny, reflective one. The light might barely reflect back from the absorbent wall, making it hard to see. In surveying, using a prism is like changing to a brighter, more reflective surface to clearly see the beam of light, thus ensuring accurate distance readings.

Problem: Data not saving
Likely Cause: Memory full or error in storage media
Solution: Clear memory or replace data card

This issue occurs when the Total Station fails to save data, possibly due to a full memory or a malfunction in the storage media. When memory is full, the instrument cannot save any new measurements. The solution requires checking the memory and either clearing it to make space or replacing the data card with a new one to ensure continued data collection.

Think of your smartphone running out of space when you try to save a new photo. Just as you would need to delete old files or get a new memory card to store more photos, a surveyor must manage the memory of the Total Station to ensure that it can continue to record crucial data accurately.

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