Differential Leveling Part 1 of 2

Summary

This educational video introduces key terms in differential leveling, including BM (Benchmark), BS (Backside), H (Height of Instrument), FS (For Sighting), TP (Turning Point), and SS (S Shot). It uses illustrations to explain how to measure elevation at turning points by taking readings from benchmarks and adjusting for instrument height. The video simplifies the process by providing a formula to calculate elevation at any turning point, emphasizing the exclusion of foresights and s shots. It aims to clarify common confusions and encourage viewers to engage with more content.

Takeaways

• 📏 BM stands for Benchmark, which is a known elevation point used as a reference.
• 🔍 BS stands for Backside, which is the reading on the scale rod over the benchmark.
• 🎯 H stands for the height of the instrument, used to find the turning point.
• 🔄 FS stands for Foresight, which is the reading on the scale rod over the turning point.
• 🔄 TP stands for Turning Point, found by taking the height of the instrument and subtracting the backside reading.
• 🚫 SS stands for S Shot, which is not part of the main line of sight and is often used to confuse or distract.
• 📉 The equation to determine the elevation at any turning point is: Elevation at TP = Elevation at BM + ∑BS - ∑FS.
• ⚠️ Do not include any S Shots when calculating the elevation at turning points.
• 🔍 The video uses an illustration to explain the terms and the process of leveling.
• 👀 The video advises viewers to be aware of S Shots, which are often used to distract in exams.

Q & A

What does BM stand for in the context of the video?

BM stands for Benchmark, which is a known elevation point used as a reference in leveling.

What does BS represent in the video script?

BS stands for Backside, which is the reading on the scale rod over the benchmark.

What is the meaning of H in the video?

H stands for the height of the instrument, which is the distance from the ground to the point where the instrument is set up.

What does FS signify in the context of the video?

FS stands for Foresight, which is the reading taken on the right side of the instrument over a turning point.

What is TP in the video script?

TP stands for Turning Point, which is a point where the instrument is turned to take a new reading.

What does SS stand for and how is it used?

SS stands for S shot, which is a reading taken not on the main line but to a point of interest, often used to distract or confuse during exams.

How is the elevation at a turning point calculated according to the video?

The elevation at a turning point is calculated by adding the elevation at the benchmark and the sum of the backside readings, then subtracting the foresight readings.

Why is the height of the instrument subtracted by the distance to the lance in the video?

Subtracting the distance to the lance from the height of the instrument helps to eliminate errors of adjustment of the instruments.

How should one approach S shots during an exam as mentioned in the video?

One should be aware that S shots are often used to distract or confuse during exams, so it's important not to include them in calculations.

What is the purpose of the illustration used in the video?

The illustration is used to visually explain the terms and the process of determining elevation at turning points in leveling.

What advice does the video give for quickly determining elevation at turning points?

The video advises using the equation provided, which does not include foresights or s-shots, to quickly determine the elevation at turning points.