1. Installation status/installation mode
In order to use the laser displacement meter to measure the target, a receiver is required to obtain the reflected light of the target. In order for the triangulation measuring instrument to properly receive the reflected light, it is necessary to install the sensor head obliquely according to the surface condition of the target.
2. The reference distance
is the point where the measured value is 0 when the target is measured by the laser displacement meter. It generally represents the distance from the bottom of the sensor head to the center of the measurement range.
3. The measurement range
indicates the range of the target displacement that the laser displacement meter can measure. Generally, the reference distance is used as the benchmark, which means ±○○ mm. For example: Reference distance: 30 mm, measuring range: ±5 mm, the laser displacement meter can measure the target within the following range.
4. The
principle of the measuring range is: in the non-contact measuring instrument, light is used to illuminate the target from the transmitter, and the receiver is used to receive the reflected light. The light source can use a variety of lights such as red semiconductor laser, blue semiconductor laser, white light, SLD, and green LED.
Decide which light source to use according to the principle of the measuring instrument, and use the lens and light receiving element corresponding to the light source to achieve high-precision measurement.
Five, light spot diameter
non-contact measuring instrument generally includes 2 kinds of light spot diameter. Divided into ellipse-shaped spot diameter and small spot type.
The diameter of the ellipse-shaped light spot can measure the average height within the ellipse, so it is not easily affected by the surface roughness error of the target. However, the spot size becomes larger, so it is not suitable for measuring shapes and small parts.
The small spot type has a smaller spot diameter and can effectively measure shapes or minute parts, but it also tracks the surface roughness. Compared with the elliptical spot diameter, it is susceptible to surface roughness errors.
6. Repeatability
indicates the deviation when repeatedly measuring the target object.
7. Straightness
Straightness is an index indicating the performance of the measuring instrument. Represents the maximum error between the ideal value and the actual measurement result. For example, when using a measuring instrument with a linearity of ±5 μm to move a 1 mm target, it means that the displayed value may include an error of ±5 μm (9.995 μm to 1.005 μm).
The specification of linearity is ±○○% of FS. FS represents the measurement range and can be calculated according to the following example. A measuring instrument with a smaller linearity can be called a better measuring instrument.
For example, linearity: 0.02% of FS, measuring range: ±3 mm (FS= 6 mm) measuring instrument, [linearity] = 0.02% × 6 mm = ±1.2 μm.
Seven, temperature characteristics The
temperature characteristics represent the maximum value of the measured value error that occurs when the temperature of the sensor head changes by 1 degree. Inside the sensor head, a lens or CMOS and a jig to fix these components are used. Due to temperature changes, the above-mentioned components will expand or contract, and changes in the position of the light spot imaged on the CMOS will cause errors.
The temperature characteristic is specified as ○○% of FS/℃, FS represents the measurement range, and can be calculated according to the following example. A measuring instrument with a smaller temperature characteristic can be called a better measuring instrument.
For example, temperature characteristic: 0.01% of FS/℃, measuring range: ±3 mm (FS= 6 mm) measuring instrument,
[temperature characteristic] = 0.01% × 6 mm = 0.6 μm.
8. The ambient light
indicates the maximum illuminance of the external light source that the measuring instrument can measure without being affected by external light.
9. The ambient temperature
guarantees the temperature environment where the measuring instrument operates.
10. The relative humidity
guarantees the humidity environment where the measuring instrument operates.
11. Anti-vibration
indicates an index that affects the vibration of the measuring instrument. Indicates that the evaluation is based on the stated value.
It is generally recorded as "10 to 55 Hz with a bidirectional amplitude of 1.5 mm for 2 hours in X, Y, and Z directions". The test is carried out as follows:
±0.75 mm amplitude in the X direction for 2 hours at a frequency of 10 to 55 Hz Change
⇓ Change
the amplitude of ±0.75 mm in the Y direction at a frequency of 10 to 55 Hz for 2 hours
⇓ Change
the amplitude of ±0.75 mm in the Z direction at a frequency of 10 to 55 Hz for 2 hours
12. Sampling period/sampling speed
means the number of data points that the measuring instrument can measure in 1 second. A measuring instrument with a sampling period of 100 Hz can perform 100 measurements per second. A measuring instrument with a faster sampling period can accurately measure an online moving target, or can perform more averaging processing within a single time, so the measured value can be stabilized.
13. The received light waveform
indicates that the state of the light received by the light receiving element is the received light waveform. The vertical axis represents the intensity of light, and the horizontal axis represents the position on the light receiving element. By confirming the shape of the received light waveform, it can be judged whether the current measurement is accurately performed.
1. Ideal received light waveform: The received light waveform can be measured stably. 
2. When the height of the received light waveform is low: sufficient reflection cannot be obtained, so measurement cannot be performed. 
3. When the height of the received light waveform is too high: in a saturated state. At this time, the deviation of the measured value becomes larger. 
4. When the shape of the received light waveform is asymmetrical: when measuring resin, etc., the laser will enter the target, making the received light waveform more asymmetrical. The measured value at this time will shift the actual value according to the incoming amount. 
5. When there are multiple received light waveforms: when measuring transparent targets such as glass, more than one peak will be generated. When measuring glass, a total of 2 peaks can be obtained from the surface reflection peak and the back reflection peak.
14. Optical axis and optical axis area
The central axis of the light irradiated by the transmitter of the measuring instrument is called the optical axis.
The optical axis area diagram shows the path of light from the transmitter to the receiver. If a jig or the like is placed in this area, the light will not irradiate the target or the receiver, so measurement cannot be performed.
15. The power supply voltage
required to drive the product. If the specification is 24 VDC±10%, it means that the DC power supply requires a power supply with a voltage variation of 24 V within ±2.4 V.
16. Maximum current
consumption The amount of current consumed when driving the product. The power supply used needs to be a product with a capacity larger than the maximum current consumption.