A tape on its own cannot survey anything. You need something to mark where the line starts, something to mark where each tape length ends, something to keep the line straight, and something to reach into hedges. Those four needs give the four accessories in this topic. 1. Pegs Pegs are used to mark definite points…
Tapes are available in a variety of materials, lengths and weights, and the choice matters more than it first appears. A tape that stretches under pull, shrinks in damp weather or expands in the sun will quietly corrupt every measurement taken with it. This post covers the four types, in ascending order of accuracy and cost….
Chain surveying is the oldest and simplest branch of the subject, and for a long time it was so dominant that surveying itself was often called chain surveying. This post covers what it is, why the equipment changed, where it works well, and the four categories of detail a survey has to record. Why It Is…
Every graduated scale has a limit — the smallest division marked on it. A vernier is a wonderfully simple device that gets around that limit, letting you read a fraction of the smallest division without adding any finer marks at all. This post covers how a vernier works, the two types, the least count formula, and how…
A plan is drawn to one scale. Someone measures it with a ruler graduated to a different scale. Every reading they take is wrong — but predictably wrong, and therefore correctable. This post covers the two correction formulas, explains why the area formula is squared, and works through a complete numerical example. The Situation If…
A map is useless unless you know how much ground each centimetre on the paper stands for. That relationship is the scale — and it turns out to be less permanent than it looks, because paper shrinks. This post covers the ways scale is expressed, why graphical scales survive shrinkage when numerical ones do not, and how…
All of surveying — every instrument, every method, every calculation — sits on just two principles. They are short enough to memorise in a minute, but understanding why they exist is what makes the rest of the subject make sense. The Two Basic Principles Principle 1: Work from Whole to Part The main idea of working from whole…
The instrument you pick decides what you can measure. A chain gives you distances but no angles. A theodolite gives you precise angles. A tacheometer gives you distance, angle and height together. Each instrument therefore defines its own kind of survey. This post covers all eight types, and — more usefully — how they rank…
Every survey is carried out for a reason, and the reason determines almost everything about it — what gets measured, how accurately, and at what scale. This post covers the six types of survey classified by purpose, together with the scales that go with them. The Six Types 1. Topographical Survey A survey conducted to obtain…
The earth is curved, but a drawing sheet is flat. Every survey has to deal with that mismatch, and there are only two honest ways to do it — ignore the curvature because the area is small enough, or account for it because it is not. That choice is exactly what separates plane surveying from geodetic surveying. This post…
