Step Height Measurement

A 1D laser displacement sensor is a reflective type sensor, which means it emits light to the surface of the measured object. That light is then reflected back to the light receiver in the sensor. Based on the changes in distance between the object and the sensor, the sensor can determine the step height measurement. High-accuracy displacement sensors are grouped into two basic categories: confocal and laser triangulation.

The laser triangulation method uses a laser diode to project a spot onto an object, which is then reflected and picked up by a light-receiving element. Distance between the object and sensor is calculated by the angle of the laser and the position of the reflected light that enters the light receiver's view. Confocal laser sensors, on the other hand, are used to obtain high-precision measurement and sometimes used to make 3D reconstruction of objects with nanometer resolution. By taking measurements of the different depths, a confocal sensor can derive the surface topography of a part and thus determine the step height measurement between different focal planes.
To efficiently measure the height of a single point, use a reflective laser displacement sensor. You can measure height at multiple locations by communicating across multiple sensors or by scanning over the target with one sensor.

Unlike 1D laser displacement sensors (which emit and pick up a single point of light), 2D laser displacement sensors project a laser line that is reflected and captured by an internal CMOS sensor. As a result, multiple data points can be measured at once. This is useful when mutiple step heights are located close together.

2D laser displacement sensors use reflected light displacement to calculate distances between the sensor and the surface of the part. Similar to 1D laser displacement, 2D relies on the laser triangulation methods to quantify step measurements.
A profile of the surface is obtained where the laser line hits, making it possible to acquire relative measurements such as step height. Even if the target is tilted, step can be measured accurately because the sensor head features an alignment adjustment function.

2D optical micrometers are typically comprised of a light emitter and light receiver, with the system employing high-intensity LEDs and telecentric lenses to focus the beam of light onto a high-speed CMOS sensor and capture images in the full field of view. When an object whose step height we're measuring obstructs the light beam, it casts a shadow or a silhouette onto the CMOS sensor, which picks it up and converts it into data that is processed by the measurement devices' internal systems and associated software.
The silhouette of the target is projected, and the step height between two specified features is calculated. Even if the shaft is tilted, step can be measured accurately when the alignment adjustment feature is utilized. Measurements are not affected by the color of the target surface.

Depending on your system of choice, you can connect one, two, or more laser displacement sensors to a single controller and have them take measurements in sync. This will provide you with an option to collect more comprehensive step height measurement data. It's worth noting that some systems support up to four laser displacement sensors, which is great for measuring step height on larger objects, such as a vehicle.

To efficiently measure the height of a single point, use a reflective laser displacement sensor. You can measure height at multiple locations by communicating across multiple sensors or by scanning over the target with one sensor.