Lasercheck® Surface Roughness Measurement Gages

OPTICAL DIMENSIONS LLC®

Measuring Principle

All Lasercheck measurement heads contain a built in visible laser source. This emits a laser beam from the bottom of the gage illuminating the surface beneath it at a shallow incident angle. After striking the surface, the laser light is reflected and scattered back into the Lasercheck detection system.

Perfectly smooth surfaces reflect just the “central” specular laser beam and there is no “diffuse” or scattered reflection surrounding that specular beam. As surface roughness increases, the "specular" laser reflection decreases in relative intensity and the "scattered light" reflection increases in relative intensity. This overall distribution of the reflected and scattered light is measured by an array of small closely packed detectors. This measurement is digitized by Lasercheck electronics, and then Ra roughness is calculated for the illuminated area.

How Does Lasercheck Work?

Light Scatter Technology

What Can Lasercheck Technology Do?

What Can Lasercheck Technology Not Do?

1. Multiple Parameters. Multiple roughness parameters require detailed profile information and Lasercheck does not actually “profile” a surface to generate the fast Ra measurement.

2. Access Deeply Recessed Surfaces. The laser beam geometry is fixed and optimized for superior results on generally flat and cylindrical shape surfaces.

3. Find Defects, Pits, Scratches. Individual features do not significantly influence the Lasercheck sensors. Lasercheck technology is optimized for superior determination of overall finish (Ra).

4. Measure “Coarse” Finishing Process. Lasercheck Light Scatter Technology is generally limited to maximum Ra of approximately 80 microinches (2.0 microns) Ra. Lasercheck is well suited to finer finishing operations like grinding, sanding, polishing, honing, “fine” shot blasting. Lasercheck is “generally” not suited to cutting and rough finishing operations like fly-cutting, hard turning, milling.

1. Measure Very Fast. Laser light signals are instantly read and analyzed. More than 10 complete Ra measurements per second can be performed.

2. Measure Very Repeatably. No moving parts. Mechanical variations are a key source of error in contact stylus measurements. They are eliminated with Lasercheck Light Scatter Technology.

3. Provide Excellent Durability. No fragile tips or mechanical devices to maintain and repair ever.

4. Automated Measurements on Moving Surfaces. The only surface finish gage that can truly perform on-line. Moving parts can be accurately measured.