What are the methods for measuring flatness?
There are many methods for measuring flatness, here are several common ones:Gap gauge measurement method: The gap gauge is mainly used for the measurement of clearance spacing, and can only be used for rough measurement of flatness.
Before use, the and dust on the gap gauge and the workpiece must be removed.
When using, one or more pieces can be overlapped and inserted into the gap, and it is appropriate feel a slight drag.
When measuring, the action should be gentle, and it is not allowed to forcefully insert.
Liquid plane method: The liquid plane method uses liquid plane as the measuring reference surface, which is composed of the liquid surface in the communicating tank, and then the sensor is used for measurement.
It is suitable for measuring theness of large continuous or discontinuous planes, but the measurement time is long and it is sensitive to temperature.
Dial gauge measurement method: The dial gauge measurement method places workpiece to be measured and the micrometer on the standard flat plate, with the standard flat plate as the measuring reference surface, and the micrometer is used to measure along the surface point by point or along several straight lines.
It is divided into the three-point method and the diagonal method: the three-point method uses the ideal plane determined by three points with the farthest distance on the actual surface to be measured as the evaluation reference surface; the diagonal method first adjusts the four corner points on the actual surface to be by two during actual measurement.
Flat crystal interferometry: The working surface of the optical flat crystal is used to reflect the ideal plane, and the degree of curvature of the fringes directly determines the flatness error value of the measured surface.
It is mainly used to measure small planes with smooth surfaces, such as the measuring surface of the dividing, the working surface of the gauge, and the optical lens.
Beam plane method: Measuring with a collimator and a target mirror, the beam plane formed by three points farthest apart on the actual surface is used as the reference plane for measuring the flatness error.
Laser flatness measuring instrument: Used to measure the flatness of large planes.
These methods have their own advantages and disadvantages, and the selection of the appropriate method depends on the size, shape, surface finish of the object to be, and the required measurement accuracy.

Recently Posted
-
Why high-precision granite platforms are the cornerstone of high-end laser equipment
May 25, 2026Reasons why high-precision granite platforms become the cornerstone of high-end laser equipmentExcellent thermal stabilityThe coef
Read More -
Provide some successful cases of special-shaped machining for granite equipment bases
May 19, 2026Case 1: Integral Custom Machined Granite Base for CMMProduct Application:High-precision bridge-type CMM base with hollowed-out wei
Read More -
The influence of humidity on precision granite surface plate
February 28, 2026The impact of humidity on precision granite slabs / marble platforms, the core is: granite itself is very stable, but humidity can
Read More -
Characteristics of Artificial Granite
February 25, 2026Characteristics of Artificial Granite▲ Material Composition and PreparationArtificial granite, also known as resin concrete or res
Read More