Aula 002 - Como medir distâncias e alturas com Nível Ótico

Summary

This instructional video provides a comprehensive guide on using an optical level for topographic measurements. It covers the essential components of the instrument, including calibration screws, the level bubble, and the decimeter scale. The instructor demonstrates how to set up and adjust the equipment, focusing on precise readings for measuring elevation and horizontal distance. Practical tips are given on proper handling, and viewers are encouraged to perform calculations to determine differences in level and horizontal distance. The video offers both theoretical insights and hands-on guidance, making it an essential resource for beginners in topography.

Takeaways

• 😀 Optical levels are essential tools in topography for measuring height differences between points, commonly used in construction and surveying.
• 😀 The setup of the optical level requires proper alignment, achieved by adjusting the leveling screws (calants) to ensure the instrument is plumb.
• 😀 Adjusting the focus screw is crucial for achieving clear vision of the target and ensuring accurate measurements, especially over varying distances.
• 😀 The bubble level on the optical level needs to be centered to confirm that the instrument is properly aligned for precise measurements.
• 😀 The Mira, a graduated scale, is used to take readings, with measurements given in decimeters, which can be easily converted to meters.
• 😀 Measurements are read from the crosshairs (fios) on the Mira, where the position of the crosshair determines the height reading.
• 😀 To calculate the height difference, subtract the reading from the Mira’s scale from the height of the instrument. Negative values indicate the target point is lower than the instrument.
• 😀 The optical level can measure only in the horizontal plane; vertical measurements require other instruments like total stations or theodolites.
• 😀 Proper handling of the optical level and Mira is necessary to avoid errors in readings. Ensure that no obstruction, such as hands, interferes with the measurement process.
• 😀 A challenge is posed to viewers to calculate new distance and height differences based on adjusted Mira readings, encouraging practical application of the learned skills.
• 😀 To verify results, use a measuring tape to confirm the calculated horizontal distance and check if the measured height difference matches the actual values.

Q & A

What is the purpose of the optical level in topographic surveying?

The optical level is used to measure height differences (levels) between two points, as well as to assist in determining the elevation for construction projects such as measuring the level of roads, dams, and buildings.

Why is it important to calibrate the optical level before use?

Calibration ensures that the optical level is perfectly aligned and stable, allowing for precise measurements. If the instrument is not properly calibrated, it can lead to inaccurate readings and errors in elevation calculations.

What are the main components of the optical level described in the lesson?

The main components include the calibration screws (for vertical alignment), the level bubble (for horizontal alignment), focus adjustment screws, and the sighting staff (Mira) for measuring elevation differences.

How do you ensure that the optical level is aligned properly before starting measurements?

You must adjust the calibration screws to align the optical level in the vertical plane and ensure that the bubble is centered. Once the bubble is centered, you can proceed with taking measurements.

What is the function of the sighting staff (Mira) in the process?

The sighting staff (Mira) is used to measure the elevation at a particular point. It has markings in decimeters, which are used to calculate the height difference between the instrument and the point being measured.

How do you read the markings on the sighting staff?

The markings on the sighting staff are in decimeters, and the position of the reading is determined by where the horizontal cross wires of the optical level intersect the staff. To convert the reading into meters, you add the appropriate value to the reading.

What does it mean if the calculated difference in level between two points is negative?

If the difference is negative, it means that the point being measured (point B) is lower than the reference point (point A), indicating a downward slope or drop in elevation.

What should you do if the bubble on the optical level moves out of alignment during measurements?

If the bubble moves out of alignment, you need to adjust the level again by using the calibration screws to re-center the bubble before proceeding with further measurements.

How can you calculate the horizontal distance between two points using the optical level?

The horizontal distance is calculated by subtracting the readings on the sighting staff for the upper and lower wires and multiplying the difference by 100. This provides the horizontal distance between the two points.

What is the significance of the challenge posed at the end of the lesson?

The challenge encourages students to apply what they have learned by measuring and calculating the horizontal distance and level difference between two points. This reinforces practical application of the surveying techniques taught in the lesson.