Online non-contact measurement scheme for width and thickness of sheet metal
I. Overview
The online non-contact laser thickness and width gauge consists of three parts: laser displacement sensor, data display instrument, and installation bracket. It has the characteristics of fast measurement speed, high accuracy, and non-contact measurement. Widely used for online measurement and control of width and thickness of various steel strips, steel plates, aluminum plates, aluminum foils, copper plates, copper foils, wooden boards, food, various rubber sheets, rubber films, plastic sheets, fabrics and other transparent and non transparent strip and sheet products.
2、 Measurement principle
The laser thickness and width gauge is composed of two opposing laser displacement sensors. During operation, the two sensors measure the distance between the sensor and the upper and lower surfaces of the measured object. The thickness of the measured object is obtained by subtracting the distance measured by the two sensors from the total distance between the two sensors. The advantage of laser thickness gauge is that it is a non-contact measurement that does not lose accuracy due to wear and tear, especially suitable for measuring moving objects.
The schematic diagram of online thickness measurement is as follows:

Schematic diagram of online width measurement:

3、 Technical parameters and performance indicators
1. Technical parameters of laser thickness gauge
Laser thickness gauge uses the principle of geometric triangle to measure the distance of the target object by measuring the laser beam emitted by the sensor, reflecting back from the surface of the measured object, and imaging the position on the CCD inside the sensor. Laser displacement sensors are mainly used to measure geometric quantities such as displacement, thickness, vibration, distance, diameter, etc. of objects, and to detect shape and size parameters such as bending, deformation, flatness, and slope of objects.
Specification Model
Model: LDS-30
Reference zero point: Zero=80mm
Measurement range: ± 15mm
Resolution: 0.001mm
Accuracy: ± 0.01mm
Light source wavelength: 670nm
Frequency response:<500Hz, operating temperature: 0~40 ℃, laser protection level: Level 2, power 1mW, power supply voltage 24V/DC, output interface: RS232/RS485; 2 sets of switches; 0-5V analog voltage output or 4-20mA current output
2. Technical parameters of laser width gauge
Technical Indicators:
scanning speed
1800 times per second
Data processors and data storage
Using high-performance DSP processors, high-speed and high-precision operations can be performed;
communication interface
RS232 and RS485 communication interfaces can be connected to a computer for online detection, and stored measurement records can also be transmitted to the computer.
Continuous measurement and data retention
Continuous measurement allows for observation of moving objects, and data retention facilitates recording,
Data parameter settings
The data parameters can be set to the nominal value and tolerance of the measured object; Out of tolerance alarm prompt;
Product specifications and technical indicators:
Model: LDM-50DZ
Range: 0.1~50mm
Accuracy: ± 3 μ m
Repetitive error: ± 2 μ m
Resolution: 0  001mm
Product physical picture: