What is Dimensional Metrology Equipment?
Dimensional Metrology Equipment is an instrument or machine used to measure the dimensions of an object.
There are various types of dimensional measuring instruments, ranging from calipers and micrometers that measure by hand to more recent types that can measure dimensions automatically and are non-contact and do not require tools.
Machine-based dimensional measurement has a smaller error margin than human measurement and can measure areas that cannot be measured with calipers and micrometers.
Applications of Dimensional Metrology Equipment
Dimensional Metrology Equipment is used in a variety of fields. Human hand-held measuring instruments such as calipers and micrometers are suitable for measuring the size of parts. On the other hand, there are many types of machine-based Dimensional Metrology Equipment, such as image and projection Dimensional Metrology Equipment, which are suitable for measuring the dimensions of products that are difficult to measure by hand because of the time required to do so.
For example, Dimensional Metrology Equipment is used not only for dimensional measurements, but also for total product inspections because of its ability to take measurements in a short period of time. The said measuring instruments can precisely measure the length, width, and phase measurement of grooves machined on shafts.
Specific examples include measuring the journal diameter of crankshafts, the outer diameter of glass tubes, the meandering of sheets, and the outer diameter of wafers. Projected dimensional measuring machines can also measure variations such as elongation and thinning during tensile testing.
Principles of Dimensional Metrology Equipment
There are many machines for measuring dimensions, including calipers, and their principles are diverse. In this section, “Image Dimensional Metrology Equipment” and “Projected Dimensional Metrology Equipment” are explained.
1. Image Dimensional Metrology Equipment
Image Dimensional Metrology Equipment captures an image of the object to be measured at a fixed distance from the image sensor of the measuring instrument. The size of the object to be measured can be determined by integrating the data of the entire image.
Non-contact imaging is possible, and even soft or large objects can be measured. For this reason, it is also used to measure the dimensions of pyramids and other large architectural structures. 2.
2. projection-type Dimensional Metrology Equipment
Projection-type Dimensional Metrology Equipment measures dimensions by shining a distortion-free parallel light on the object to be measured and projecting its silhouette onto a screen in an enlarged image. Since the magnification rate is constant, the original dimensions of the object to be measured can be determined by measuring the dimensions of the magnified image.
The advantages of this non-contact measurement method are that it can measure small and complex shapes. There is also a type that measures from the image of the object to be measured by reflecting illumination from the object to be measured.
Types of Dimensional Metrology Equipment
There are various types of Dimensional Metrology Equipment other than those mentioned above. There are two main types: Mechanical Dimensional Metrology Equipment and Manual Dimensional Metrology Equipment.
1. Mechanical Dimensional Metrology Equipment
There are many types of mechanical Dimensional Metrology Equipment other than “Image Dimensional Metrology Equipment” and “Projected Dimensional Metrology Equipment. This section describes commonly used dimensional detectors other than those mentioned above.
- Laser Displacement Meter
Laser Displacement Metrology Equipment is a Dimensional Metrology Equipment based on Triangulation. It measures dimensions by irradiating a laser beam onto the object to be measured and detecting the reflected light, and the sensor that detects the reflected light is positioned at an angle to the direction of the laser beam.When the reflective surface of the object to be measured is raised or lowered perpendicular to the direction of laser irradiation, the light-receiving surface of the sensor is displaced, allowing measurement of thickness and other parameters based on the difference from the reference surface. In addition to the above-mentioned method based on triangulation, there are also multi-color confocal and confocal methods of laser displacement measurement.
- Laser Transmission Type O.D. Measuring Instrument
Laser transmission-type O.D. measuring machines are devices that measure dimensions from the projected image of the object to be measured as the laser scans it. The outside diameter is measured by comparing the area where the laser beam is blocked by the object to the area where the laser beam is unobstructed. The most common laser beam irradiation method is a method in which a multi-faceted mirror rotates and reflects the laser beam to form a parallel laser beam.
2.Dimensional Metrology Equipment
Dimensional Metrology Equipment is often used in the field of metalworking.
- Calipers
Calipers are the easiest to use in metalworking. The object to be measured is clamped between two claws, one on the fixed reference side and the other on the movable measuring side, and measured in 0.05 mm increments. - Micrometer
Like the caliper, the micrometer clamps the object to be measured with a dial gauge and measures it. However, micrometers can measure in increments of 0.01 mm and are more precise than calipers. - Dimensional Metrology Equipment with No Moving Parts
Dimensional Metrology Equipment without moving parts include pin gauges, limit stopper gauges, block gauges, and gap gauges. These are very precisely machined for a given size and have no moving parts.For example, in the case of a pin gauge, the diameter of the pin is so precisely machined that if the pin can be inserted into the relevant hole, the accuracy of the machining is considered to be maintained.