Linear measurement corrections – sign convention Under conventional surveying sign conventions for line corrections, which of the following corrections is assigned a negative sign?

Introduction / Context:
Precise linear measurements require applying systematic corrections to observed tape/EDM distances. Understanding the algebraic sign (add or subtract) for each correction avoids propagating bias into traverse closures, control networks, and construction setout.

Given Data / Assumptions:

• Conventional practice: corrected (true) length = measured length + sum of corrections.
• Measured length may be along slope or along a slightly misaligned path.
• Heights above mean sea level and reduction to MSL are considered for geodetic work.

Concept / Approach:

Several corrections reduce the measured value to a smaller true value and are therefore assigned negative signs in the additive correction model. Reduction to mean sea level shortens the ground distance to an equivalent MSL arc/chord; slope correction reduces an inclined distance to its shorter horizontal projection; horizontal alignment correction removes excess length caused by small departures from a straight alignment between end points. Each of these therefore carries a negative sign when added to the measured length.

Step-by-Step Solution:

Verification / Alternative check:

Worked examples in surveying texts consistently subtract these corrections from measured distances. By contrast, temperature and pull corrections can be positive or negative depending on conditions relative to standard values.

Why Other Options Are Wrong:

Options restricting the negative sign to only one or two corrections omit other equally negative adjustments; hence the comprehensive choice is correct.

Common Pitfalls:

Confusing the algebraic sign convention between “apply by subtraction” and “add a negative”; failing to separate random errors (treated statistically) from systematic corrections (applied deterministically).

Final Answer:

All of the above