What's the difference between a profilometer and a surface roughness tester?

Some people are confused about the differences and similarities between profilometers and roughness testers. Today, we'll explain the differences and similarities between the two.

Similarities:

Both profilometers and roughness testers are surface topography measuring instruments.

Profilometer

Definition

A profilometer is an instrument that can measure the waviness and roughness of a workpiece's surface and provide numerical values. It uses a precision air-bearing guide as a linear reference. A profilometer is an instrument that tests and inspects an object's contour, two-dimensional dimensions, and two-dimensional displacement. As a precision measuring instrument, it is widely used in the automotive and railway industries. It is a precision device that measures the linear shape and cross-sectional profile of various mechanical parts. In the bearing industry, it can measure the linear shape of various rolling elements and raceways, such as protrusion, contact angle, surface curvature radius, and reference part angle.

Functions

The profilometer can measure the contour parameters of various precision mechanical parts, including angle processing (coordinate angle, angle with the Y coordinate, angle between two lines), circle processing (arc radius, center-to-center distance, center-to-line distance, intersection-to-center distance, line-to-tangent distance), point-line processing (intersection of two lines, intersection-to-line distance, intersection-to-intersection distance, intersection-to-center distance), straightness, convexity, logarithmic curves, groove depth, groove width, groove curvature radius, groove side distance, groove center distance, profile, horizontal distance, and other shape parameters.

Working Principle

A profilometer is a two-coordinate measuring instrument. Its sensor slides at a constant speed relative to the workpiece surface. The sensor's stylus senses geometric changes in the surface, sampling in the X and Z directions and converting them into electrical signals. These signals are amplified, processed, and converted into digital signals for storage in the computer system's memory. The computer digitally filters the raw surface profile, removing the surface roughness component before performing calculations. The measurement result is the calculated actual value of a curve and its coordinates relative to a reference point, or a magnified actual profile curve. The measurement results are displayed on a display or can be printed.

Features of a profilometer

High precision, high stability, and high repeatability: fully meeting the measurement accuracy requirements of the workpiece.

(1) High-precision grating measurement system and high-precision inductance measurement system are selected to achieve high measurement accuracy;

(2) High-precision grinding guide rail system is independently developed, and the guide rail material has good wear resistance, ensuring stable and reliable operation of the system;

(3) High-performance linear motor drive system ensures high measurement stability and good repeatability;

Application

The profiler is widely used in mechanical processing, automobiles, motorcycles, precision hardware, precision tools, cutting tools, molds, optical components and other industries. It is suitable for scientific research institutes, colleges and universities, metrology institutions and enterprise metrology rooms.

In the automobile, motorcycle and refrigeration industries, it can measure the busbar parameters of pistons, piston pins, gears and valve push rods of automobiles, motorcycles and compressors. It can also measure the parameters of various oblique parts.

In the bearing industry, it can measure the shape of the sealing grooves of inner and outer rings (angle, chamfer R, groove depth, groove width, etc.); the convexity, angle, and logarithmic curve of the roller and ring generatrix of various roller bearings; the straightness of the rolling elements and rings of motor shafts, cylindrical pins, piston pins, needle roller bearings, cylindrical roller bearings, and linear bearings; the groove curvature radius and groove edge distance of ball bearing grooves; the groove center distance of double-groove bearings; and the groove center distance and groove curvature radius of four-point contact bearings (peacock grooves).

Profilometer

Roughness Tester

Definition

Roughness testers are also known as surface roughness testers, surface finish testers, surface roughness testers, roughness measuring instruments, roughness meters, and roughness testers. They feature high measurement accuracy, a wide measurement range, simple operation, portability, and stable operation. They are widely used for inspecting various metal and non-metallic machined surfaces. This compact instrument integrates a sensor and a main unit, making it handheld and suitable for on-site use. Its rugged design and excellent electromagnetic interference resistance align with today's new design trends.

The core value of a roughness tester lies in its ability to accurately quantify the microscopic features of an object's surface. By employing advanced sensing technology and sophisticated measurement algorithms, it can convert minute surface irregularities into quantifiable data. This data, including key parameters such as average roughness height, peak-to-valley spacing, and profile shape, provides a comprehensive understanding of the surface quality. For example, in the machinery manufacturing industry, the surface roughness of a part directly affects its friction performance, fit accuracy, and service life. The precise measurements provided by a roughness tester can help engineers determine the optimal machining process and surface treatment methods to ensure that part quality and performance meet design requirements.

Operating Principle

The operating principle is primarily based on advanced technologies such as stylus or optical methods. Stylus roughness testers use a tiny diamond stylus to move across the surface, recording changes in the vertical displacement of the stylus. Optical roughness testers, on the other hand, utilize the reflection and scattering of light to perform non-contact surface measurements. These advanced measurement technologies enable roughness meters to accurately measure surfaces of various materials and shapes, from hard metals to soft plastics and even complex curves.

Advantages

Roughness meters also offer advantages such as ease of operation and portability. Modern roughness meters often feature intelligent designs, intuitive displays, and simple user interfaces, enabling quick user experience and accurate measurement. Portable roughness meters can also be easily carried on-site for measurement, meeting the needs of diverse work environments.

Applications

Roughness meters have a wide range of applications. In automotive manufacturing, the surface roughness of key components such as engine blocks, pistons, and crankshafts significantly impacts engine performance and reliability. Roughness meters can rigorously inspect the surfaces of these components to ensure they meet high-quality standards. In the electronics industry, the surface roughness of printed circuit boards (PCBs) impacts soldering quality and signal transmission performance. Accurate measurements using roughness meters can optimize PCB manufacturing processes and improve product quality and stability. In aerospace, the surface roughness of aircraft components is crucial to aerodynamic performance and flight safety. The use of roughness testers helps ensure that every component's surface quality meets the highest standards.

With the continuous advancement of technology, higher demands are being placed on the performance and functionality of roughness testers. Future roughness testers will be more intelligent, highly precise, and multifunctional. Furthermore, integration with other testing equipment and systems will become a growing trend, providing even stronger support for comprehensive quality inspection and control.

Comparison Table