The methods of measuring steps are divided into contact type and non-contact type. If there is no high requirement on the accuracy and speed of measuring the steps, and you don't mind scratching the surface of the product when measuring, and the material is not soft or sharp, you can choose the contact step meter to measure the steps. Stepper usually consists of mechanical probe and measuring system. The mechanical probe can be a sharp needle tip or a spherical probe, which will contact and move along the surface to be measured. When the mechanical probe contacts the measured surface, the measuring system will record the movement track and force change of the mechanical probe. By measuring the movement and force change of the probe on the surface, the surface topography parameters can be calculated. The key in the measurement principle is the contact and movement between the probe and the measured surface, so it is necessary to ensure the stability and accuracy of the probe. In addition, the influence of surface hardness, smoothness and other factors on the measurement results should also be considered. However, the contact step instrument is prone to the phenomenon of firing pin in the measurement process, and the service life of the instrument is short.

If there are requirements for measuring accuracy and speed, or if the product to be measured is difficult to be measured with a contact step meter, such as soft materials or sharp products, or if you want to measure in a non-contact way without damaging the product, you can choose a white light interferometer driven by piezoelectric ceramics to carry out step measurement.

The white light interferometer driven by piezoelectric ceramics uses optical principle to measure steps, which can realize nondestructive testing and will not scratch the product surface. The measurement accuracy can reach sub-nanometer level;

Multi-line measurement can be realized, and more sections than probe types can be quickly selected to ensure measurement stability;

Soft and sharp products that can't be measured by contact step meter can also be measured by white light interferometer;

The software is rich in functions, automatically measuring the highest point and lowest point, average value, statistical analysis and so on.

It can measure the height of transparent products, and the surface with reflectivity as low as 0.02% can also easily collect point clouds for imaging;

Under the condition of the same amplification accuracy, the white light interferometer can obtain a larger field of view and scan in the form of plane, which can generally complete the measurement in a few seconds, and the scanning speed of AM-7000 series can reach 400 microns/second.

To sum up, you can choose the step detector with different measuring principles according to your own needs.