The Edge Break Sensor

The edge break sensor is a compact handheld optical sensor prototype used by operators in the workshop environment to identify micron sized defects without the time consuming processing of taking a wax mold and measuring that mold on a profilemeter. The system was designed and built in partnership with a large industrial manufacturer and is undergoing field testing.

System Description

The handheld sensor captures surface profile information: it works by projecting a pattern of lines onto the region of interest and then capturing images of that pattern for evaluation with software. Using LED optics, this pattern in created by projecting a LED through a grating (shown in green). The grating sits on a piezo stage which moves to three positions.

A second optical channel includes a camera with a zoom and focusing lens (shown in red). This optical channel collects three images of the grating pattern. These three images are used by a software application to extract profile information.

The Edge Break Sensor 1
The Edge Break Sensor 2


The Edge Break Sensor 3


The Edge Break Sensor 4


RequirementNumerical valueUnits
Measure radii max0.050Inch
Measure radii min0.005Inch
Absolute calibration0.001Inch
Measure straightness of facets0.0005Inch
Working DistanceHandheld, contact 
Field of View at part0.125Inch
Exposure Times1-100msec
Supply Voltage100 – 240 Volts AC/50-60 Hz 
Sensor Tips ProvidedStraight, right angle, fast change 
Battery BackupUPS with x hr capability 
Sensor Size8 x7 x 3  w/handle 
Sensor FocusManual 
Image and profile analysis platformWindows XP PC 
Sensor ControllerWindows XP PC 
Sensor InterfaceFirewire 
Light sourceLED