1. According to whether the measured parameter is measured immediately or not, it can be divided into immediate measurement and indirect measurement.

Immediate measurement: Immediately measure the measured parameters to obtain the measured size. For example, measure with Vernier scale and comparator. Indirect measurement: Measure the geometric parameters related to the measured size, and obtain the measured size through calculation.

Obviously, immediate measurement is more visual, while indirect measurement is more complex. Generally, when the measured size or immediate measurement cannot meet the accuracy requirements, indirect measurement is unavoidable.

2. Hardware small processing is divided into touch measurement and non touch measurement based on whether the measured surface touches the measuring head of the measuring tool.

Touch measurement: The measuring head is in contact with the surface being touched, and there is a measuring force that has the effect of mechanical equipment. For example, use Vernier scale to measure parts.

Non touch measurement: The measuring head does not touch the surface of the measured part, and non touch measurement can prevent the measurement force from harming the measurement results. For example, using projection method and light wave intervention method for measurement.

3. According to the common situation of the tested parts throughout the measurement process, the processing of hardware accessories is divided into static data measurement and dynamic measurement.

Static data measurement; Measure relative stillness. For example, measure the diameter with Vernier scale.

Dynamic measurement; Measure the relative velocity between the measured surface and the measuring head during simulated operation.

The dynamic measurement method can reflect the condition of the parts in close proximity to the application situation, which is the development prospect of measurement technology.