What does planimeter mean?
A planimeter is an instrument used to measure the area of a two-dimensional figure, particularly an irregular area that cannot be measured easily with a standard geometric formula. Traditional planimeters work by tracing the boundary of a shape with a pointer, while the instrument's mechanism integrates the movement to calculate the enclosed area. Mechanical versions were widely used in surveying, engineering, and cartography, while digital and electronic models are now common for analyzing drawings and maps. The word is technical rather than everyday, but it remains useful in fields where accurate area measurements are important. It should not be confused with planimetry, which is the mathematical discipline or method of measuring areas, or with a planisphere, which is a flat representation of a globe.
nounA mechanical or electronic instrument for measuring the area of a two-dimensional figure, especially an irregular area whose outline can be traced with a pointer.
- An instrument used to determine the area of a plane figure by tracing its boundary or by integrating measurements of its shape.
"The surveyor traced the boundary of the parcel with a planimeter to calculate its area."
"Using a planimeter, the cartographer measured the area enclosed by the map's irregular coastline."
"The museum technician checked the drawing's dimensions with a digital planimeter before restoring it."
The standard plural of planimeter is planimeters.
"Several planimeters are used in the laboratory for measuring the areas of prepared specimens."
A planimeter turns the act of tracing an irregular outline into a mathematical area measurement.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of planimeter
Planimeter combines the Latin-derived combining form plani-, meaning plane or flat, with the Greek-derived element -meter, meaning measure. The term developed through French and other European languages as the name for an instrument that measures areas on a plane. Related words include plane, planimetry, planographic, and planal, all reflecting the same broad association with a plane surface or planar measurement.
How planimeter is actually used
The word is technical and relatively uncommon in general use. In surveying, cartography, and engineering, it usually refers to a mechanical integrating instrument; modern instruments may also use digital or electronic sensing.
Easily confused with planimeter
A planimeter is an instrument that measures area, whereas planimetry is the mathematical method or field of measuring areas on a plane.
A planimeter measures the area of a figure, while a planisphere is a projection of the globe onto a flat surface.