- Non-contact measurement using optical sensors
- Increased efficiency through precise performance monitoring of your system
- Control over the utilization of your system from anywhere and at any time
- Flexible use: especially for mobile systems, also for short belts, belts with carriers, and metal belts
- Independent of belt tension and inclination changes – for reliable weighing results
- No recalibration required – low maintenance and durable
- Mounting without modifications to the conveyor belt – easy installation and commissioning
- Global access through data transmission via SIM card
Folgende Unternehmen nutzen diese Lösung
Kali + Salz AG
Sonntag Baugesellschaft mbH & Co. KG
Wibrek GbR
AGH Steinwerke GmbH
How the optical belt scale works
The optical belt scale measures the volume flow on the conveyor belt without contact. Depending on the belt width, different numbers of lasers are used.
- Measurement of the material profile:
The laser beams hit the surface of the conveyed material and are reflected. A photodiode detects the reflections and determines the layer height of the material using triangulation. The large number of sensors enables the exact optical measurement of the material profile on the conveyor belt. - Determination of speed:
Parallel to the material profile measurement, an inductive sensor measures the speed of the conveyor belt. - Calculation of the volume flow:
The sensors combine the speed and cross-sectional profile of the material to calculate the current volume flow in m³/h. The electronics store this data and integrate it to give the absolute quantity conveyed in m³. - Product-dependent mass conversion:
Different material densities can be stored in order to convert the volume flow (m³/h) into a mass flow (t/h) and absolute masses (t). - Data transmission and storage:
The recorded values are stored for up to one year and can be accessed via various wireless interfaces. Calibration and adjustment are carried out using easy-to-use software on a robust mobile device. Direct transmission of the data to a web server provides worldwide access to the measurement data from the optical belt scale. - Output signals for stationary applications:
For continuous operation in stationary systems, an analog output (4–20 mA) for real-time transmission of the flow rate and a pulse output for total quantity recording are available, among other things.
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| Belt widths: | 600 to 1,800 mm (larger widths available on request) |
| Dimensions (LxWxH): | 663 to 1,815 x 160 x 137 mm |
| Weight: | 7.1 to 20.7 kg |
| Power supply: | 24 VDC (+/-20%), 5 A |
| Operating temperature: | –45 °C to +70 °C |
| Measurement points/second: | 3,200 |
| Measurement accuracy for distance measurement: | +/- 0.4 mm |
| Number of measuring lasers: | 13 to 16 |
| Max. mounting height: | up to 950 mm |
| Max. layer height on the belt: | up to 680 mm |
| Laser class: | IEC 60825-1:2001 Class 3b |
| Pulse power Pmax: | 60 mW/laser |
| Pulse duration / pulse: | 400 µs |
| Laser wavelength l: | 785 nm |
| Pulse repetition rate: | 200 Hz |
| Memory for measurement data: | Up to 1 year |
| Interfaces: | Bluetooth (standard), analog output 4–20 mA, pulse output, serial interface RS-422 (4-wire) |
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Compared to a gravimetric belt scale, an optical belt scale can be installed with virtually no modifications to the conveyor system. The optical belt scale is installed above the conveyor belt using the frame supplied, for example, and the speed is measured by a sensor on the conveyor belt's deflection drum.
The standard version measures up to 400 mm layer height. The maximum conveying capacity therefore depends on the belt width and speed – throughputs of over 1000 m³/h are easily possible. The minimum resolution is 1 mm; an average layer height of at least 50 mm is recommended.
Typical applications are:
- Mobile plants, e.g., crushers, screens, and shredders
- Balancing of material flows
- Applications where volume rather than mass is required
- Process monitoring
- Monitoring of plant performance and operating hours
- Increased efficiency
- Tunnel boring machines
- Mobile or short conveyor belts
- Truck loading
Since there are no moving parts in the device, periodic maintenance is generally not necessary. Even with highly dusty products, cleaning is rarely required. If necessary, the covers of the laser and photodiodes should be cleaned occasionally to ensure optimal measurement performance. The system indicates when lasers are dirty.
- Sensor head with integrated electronics including data memory
- Proximity switch for speed measurement
- Steel or aluminum frame for mounting the sensor and installation on the conveyor belt
- Robust handheld device with Bluetooth interface for setting and adjusting the scale
- Cables required to connect all components and power supply
- Optional: Analog outputs, compact printer, or serial interface for alternative data transmission, remote data transmission via mobile network
Originally developed for the recycling industry, they are now used in numerous applications, including:
- Mobile crushing and screening plants
- Lightweight and shredded materials
- Waste and wood processing
- Volumetric measurements in various industries
- and much more.
Compared to a gravimetric belt scale, an optical belt scale can be installed with virtually no modifications to the conveyor system. The optical belt scale is installed above the conveyor belt using the frame supplied, for example, and the speed is measured by a sensor on the conveyor belt's deflection drum.
A one-time zero calibration is required. During this process, the scale stores the profile of the empty conveyor belt. A control weighing with a known volume is not absolutely necessary, but is recommended to check the measuring accuracy.