Online Diameter Gauge

With machine vision as the core, DBM can provide intelligent equipment R&D, manufacturing, and transformation services such as unmanned factories in the metallurgical industry and other industries, machine vision, and robot application design.

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Product introduction

diameter measuring instrument


We offer many types of measurement instruments for the steel manufacturing industry. If you have requirements for intelligent measurement of diameter, length, thickness, etc for your steel products, we will always find a solution for you.


This model of equipment is mainly used for online size detection of hot-rolled anchor steel and rebar production lines.



Advantaged Of Our Diameter Measuring Instrument

1 Performance advantages of the caliper

1) The measurement is accurate, and the dynamic error of measuring round steel is not more than 0.01mm. The dynamic error of the rebar is not more than 0.06mm.

2) The unique jitter error elimination technology eliminates the measurement error caused by the jitter of the rolling material.

3) Fully digital high-frequency measurement system, the measurement frequency is as high as 2000Hz, that is, 2000 rolled sections are measured per second

4) It can detect the common defects of round steel, such as: “ear”, “wrong roll”, etc.

5) Measurement data alarm function.

6) Historical data queries can be provided.

2 High precision, calibration-free

The DBM caliper adopts an optical path system that has been strictly designed and calculated, and the imaging boundary is clear. And the whole series of products are adjusted according to the accuracy of 3 microns, reaching the international leading level of large-diameter measuring instruments. During normal use, the caliper is free from calibration for all dimensions within the range, providing users with unprecedented convenience.

3 Provide an external database

In addition to the storage and analysis functions of the measurement data, the software also provides an external database, which is convenient for users to process, organize, analyze, calculate, and count the measurement data according to their own needs.

4 Powerful defect detection capability

The software can detect the wrong roll, ear, head defect length, and tail defect length of the bar, providing strong quality support for actual production.

5 Excellent protection performance

The caliper is designed according to the protection level of IP54 to prevent dust from entering, prevent splashing water from entering, resist high temperatures, resist electromagnetic interference, and adapt to harsh operating environments.

6 independent steel guides

It is recommended to use an independent steel guide for this equipment and use the rolling line guide trough directly, and the steel passing parts are neither connected nor contacted with the caliper. The impact and vibration of the steel guide groove will not affect the caliper, which reduces the factors that cause the caliper to fail and saves the purchase and management costs of the special guide groove.

7 high-brightness LED light source

The LED light source imported from the United States equipped with the measuring head of the DBM caliper has high brightness, long life, and strong temperature adaptability.

★ The highest brightness can reach 3000mcd. Even in the case of slight dust pollution on the window lens, the diameter measurement is normal, which prolongs the maintenance cycle of the diameter measurement instrument;

★ The normal service life is more than 80,000 hours;

★ The ambient temperature -20℃~50℃ can be used normally, and the environmental adaptability is better than that of the laser lens.

8 High-frequency measurement

The scanning frequency of the caliper depends on two conditions: one is the CCD chip with high scanning frequency; the other is the digital signal acquisition system. The DBM caliper adopts a new high-frequency linear array CCD chip with a scanning frequency of 15MHz, combined with the fully digital signal acquisition system independently developed by the company, and the sampling frequency can reach 1000Hz

sampling interval

Advantages of high-frequency measurement: When measuring high-speed rolling products, the higher the measurement frequency, the smaller the interval between measurement points, and the higher the probability of detecting product defects. As shown in Figure 2.1, it is assumed that the rolling speed of the rolled material is 100m/s, and there are 6 defect points within each meter. When the measurement frequency is 100Hz, at most one defect point can be detected per meter; when the measurement frequency is 2000Hz, it is possible to detect multiple defect points within 1 meter.

9 Industrial computer calculation, stable performance

At present, the data processing method of most manufacturers’ diameter measuring instruments is that the single-chip computer calculates the final result, and then transmits it to the industrial computer for post-processing. Such a circuit system has poor adaptability to the environment of high temperature, high dust, and strong electromagnetic interference at the steel rolling site. In order to improve the environmental adaptability and performance stability of the caliper, Lanpeng has developed a circuit system that directly transmits the collected raw data to the industrial computer for calculation. The adaptability of the caliper to the field environment is improved, and the operation stability of the whole set of equipment is greatly improved.

10 Techniques for Eliminating Jitter Errors

In the caliper industry, the measurement error caused by the jitter of the measured object has always been a problem that plagues the technicians in the industry, and other manufacturers have not solved it so far. After painstaking research, our company took the lead in solving this problem in the industry by adopting multiple synchronization technologies such as light source-signal acquisition unit pulse synchronization, multi-channel acquisition synchronization, signal acquisition-communication transmission synchronization, etc. It eliminates the jitter error and fills the gap in domestic technology.

11 The LED display is large and full of functions

The on-site LED display screen configured by Lanpeng Caliper has an overall size of 1550mm×1070mm, a data word height of about 150mm, and a visual distance of more than 30m, which is convenient for on-site operators to monitor in time. The LED display screen has an on-site alarm function. The specific alarm method is: when the three detection index values of the tested rolled material are within the normal range, the font of the index will be displayed as “green”. When one or more detection index values of the tested rolled material are in the upper tolerance, the value of the corresponding indicator will change to “red”, and the running status will be displayed as red “out of tolerance”; When the value of one or more detection indicators is in the lower limit, the value of the corresponding indicator will turn “yellow”, and the operation status will be displayed in red “out of tolerance”.

12 Easy maintenance

There are only two daily maintenance items for this set of equipment, namely, the wiping of the window lens and the cleaning of the fan filter element. The maintenance cycle, maintenance method, and time of these two items are as follows:

★ The maintenance cycle of window lenses is about 20 days. During maintenance, remove the sealing ring on the caliper, wipe the window lens clean with a lens cleaning cloth, and then install the sealing ring. Lens maintenance only takes about 10 minutes once.

★ The maintenance cycle of the fan filter element is 1 to 2 weeks (depending on the site environment). During maintenance, take out the filter element from the filter housing, drop it lightly on the ground, or use a compressed air duct to clean the dust on the filter element. Maintenance takes no more than 10 minutes.

★ Open the door for maintenance, easy to clean and wipe the lens, and the operation is more convenient.

Product Details

1. Product introduction:


The diameter measuring instrument has 3 built-in industrial cameras, which can take images from different angles by using the self-illumination of anchor rods and rebars during hot rolling and using the backlight to take clear images during cold rolling. It can measure the inner diameter, outer diameter, rib height, pitch, and other characteristic dimensions of the rolled material.


2. Measuring principle

Measuring principle


3 Equipment composition


equipment composition


4. Function description:

Function description

Measurement characteristic values:

Anchor steel inner diameter d0, anchor steel outer diameter d1; anchor steel diagonal dimensions d2, d3;

Pitch p, relative offset dimension of transverse ribs on both sides p/2


Product parameter setting:

Parameters such as product specifications, and positive and negative tolerances can be set;

System parameter setting:

You can set the faulted channel, communication port, thermal expansion coefficient, etc.;

Data storage:

For data records, the storage time is more than 1 year; for historical data queries, the size at a certain moment can be queried, and the time is accurate to the second.

Alarm settings:

The form and threshold of over-tolerance and over-temperature alarms can be set;

Correction function:

Automatic/manual, calibrate after inputting the thermal expansion coefficient.

Over-tolerance alarm:

Related data color warning and buzzer sound alarm in the main control room; on-site LED display data color and status display alarm.

Over-temperature alarm:

Measure the temperature sensor in the car, when the temperature in the car exceeds the temperature range of the camera, the alarm light in the main control room will light up and alarm; the on-site LED display status will display the alarm.


5. Application scope


The equipment is mainly used for online size detection of hot-rolled anchor steel and rebar production lines.


6. Technical parameters:

Model Measuring range


rolling diameter


Measurement accuracy




Measurement frequency




Weight (KG)
JX03-DG35 0-35 6-25 ±0.06 0.02 50 1500×800×1250 200
JX03-DG50 0-50 6-40 ±0.06 0.02 25 1500×800×1250 240

round bar diameter


The measuring instrument adopts the smart workshop IoT sensor data acquisition system

In the industrial Internet of Things scenario, the workshop needs to transmit the data collected by the equipment sensors to the central control system in real-time through the network, to perform real-time monitoring and predictive maintenance on the working environment, product status, and equipment operation. Therefore, it is not difficult to see that the collection of sensor information has also played a great role in the development and promotion of the industry.

In addition, we can also transmit the workshop data in the form of modules to the higher-level MES system and ERP system through various Internet of Things platforms and various protocols, to facilitate the overall management and operation of the enterprise, so that the scale of the enterprise Real-time management of growth and products, enhanced stability requirements, and reduced operation and maintenance costs.

Through the information management of the production process, the modified system can realize the visual management of the production plan, visual management of the production process, visual management of equipment status, and visual management of the assembly process, thereby reducing the cost of equipment and material management, and reducing the transmission of equipment information and management information waste, thereby improving product quality, reducing defective products, and providing a strong impetus for the company to pursue cost reduction, eliminate defective products, pursue zero inventory, and pursue comprehensive, efficient, flexible and high-quality services.

Based on such advantages, everyone can’t help but wonder: How is the workshop IoT sensor data acquisition system constructed, and what are its specific data links and operation steps? Next, let’s take a look together.


Data link transmission

date link

1/ Each measuring device converts the detection signal into digital information, assembles it into structured data, transmits it through the network, and finally reaches the display terminal.

display terminal

2/ The rule engine module of the acquisition system filters, enriches, and converts the raw data obtained by the sensor, outputs numbers, fluctuation graphs, histograms, etc. in real-time, and stores them in the database and local server in the review background.

3/ The server can back up the data to the cloud through the Internet, and display it to the control center and other end users.


Choose the right equipment and solutions

diameter measuring instrument

1. Sampling various product parameters and professional equipment in the workshop production line to determine various monitoring constants, width/thickness/diameter/length/height/section profiles, and other data. If you want to obtain some special values, you may also require custom special equipment.

2. Select the equipment, and the sensor monitoring data that is different from the data flow scheme of the configuration products mentioned above. What also needs to be considered is the specific development of the software terminal.

3. Carry out business development on the server, determine the required functions, determine the receipt of device data and issue control instructions.

4. The server program establishes a connection with the sensor, associates with the feedback terminal, and performs the overall joint debugging operation. The last point is related to the data reported by each device. It is also the most critical step. Professional staff must be installed and debugged.

DBM has independently developed a variety of photoelectric measurement systems. Hardware products such as diameter gauges, width gauges, thickness gauges, profile gauges, and straightness gauges can reach a maximum accuracy of 0.01mm, and independently developed DBM measurement and control 2.0 professional measurement and control The platform can provide customers with mature measurement and control solutions for metallurgical production lines in various scenarios, and contributes China’s strength to building smart production workshops in the steel industry.


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Length measuring instrument – For online length detection of hot-rolled bars, steel pipes, non-ferrous metal bars, pipes, etc.





LIAONING MINERAL & METALLURGY GROUP CO., LTD . was established in 2007.
Our products are widely used in steel, electric power, hospitals, welding and other fields. With machine vision as the core, it can provide intelligent equipment research and development, manufacturing and transformation services such as unmanned factories in the metallurgical industry and other industries, machine vision, and robot application design.

We are committed to becoming a “leader in visual applications”, advocating the core values of “integrity, cooperation, innovation, expertise, and excellence”, taking the road of “technology shaping the brand, innovation leading the industry”, and attaching importance to the investment in scientific research and technology. The research and development of new products and the construction of the team make unremitting efforts for the goal of scientific and technological development.

We have been supplied to world’s top steel manufacturer Arcelormittal, TATA Steel, EZZ steel etc. We do OEM for Concast and Danieli for a long time

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