The present invention relates to an online scanning laser thickness monitoring instrument. The scanning laser thickness gauge is widely used in various transparent and non transparent plates, sheets, foam plates, hollow plates and artificial leather. Thickness measurement of products such as rubber sheets, rubber curtains, films, thin films, glass sheets, composite sheets, metal sheets, etc. during operation. The precision "mouth" shaped scanning mechanism is used to continuously scan the measured object left and right in the width direction. The industrial computer serves as the main processor and has functions such as data processing, scanning measurement, arbitrary point fixed-point measurement, graphic curve display, deviation alarm, data storage and query, reporting, printing, quality rating (CPK), and control.
Working principle
The instrument uses the light cutting method to measure the thickness of the measured surface. Its working principle is shown in the figure. A set of laser probes are installed on top and bottom respectively. The light emitted by the laser source passes through the slit and forms a long bright line, which is irradiated on the surface of the measured object at a 45 ° angle. A surface with thickness variation, when illuminated by long bright lines, produces reflection at point S when the thickness is H, and reflection at point S' when the thickness is h. Their imaging is captured by a lens at points A and A 'of the image sensor CCD. The distance N between point A and point A 'is measured through data processing, and the thickness change △ h of the measured surface is as follows:
△h=H-h
=COS45°N/V
The thickness value displayed by the instrument=constant+△ h
V=lens magnification
Figure 1: Principle of Single Probe Measurement
If the tested board has rigidity and cannot reliably contact the roller, the true value cannot be measured. This requires installing a probe on each surface of the board to form the measurement method shown in Figure 2.
Figure 2 Principle of dual probe measurement
The probe collects signals and sends the CCD signal to the industrial computer for data acquisition, processing, display, alarm and other operations.
Functional Features
1. Using laser reflection measurement method, continuous non-contact and non-destructive thickness measurement of the measured object is carried out, which is not affected by the material of the measured object. It has the characteristics of no radiation, good safety performance, fast response, simple maintenance, stable performance, and high accuracy;
2. It can be scanned and measured online, as well as measured at any point;
3. Easy to operate, user-friendly human-machine interface, simultaneous display of graphical curves and data, and clear visibility of thickness changes;
4. Display mode: Point line chart displays data curves, and can also be displayed as curve chart or bar chart, which can be freely set;
5. Parameter settings: Users can set standard thickness values, upper tolerance limits, lower tolerance limits, product management (including production batches, shifts, materials used, and producers) according to production requirements;
6. System calibration: Calibrate the system through orbit calibration to ensure accurate measurement;
7. Usage permissions: User permissions are divided into four levels: super administrator, administrator, process technician, and operator, with clear management permissions to ensure quality and safety.
8. Detailed data report:
a. Product information: including the production batch, shift, material used, and producer of the product;
b. X-R control chart: Analyzing and judging the status and quality of the process, it is a waveform for comprehensively controlling the quality status. It has two prominent features: one is wide applicability, and the other is high sensitivity;
c. CPK: Analyze and rate product quality, and provide quality control recommendations;
9. Data saving: Real time saving, can be viewed through EXCEL, and can be saved for up to 1-3 years;
