Sensors & Transducers


A belt 'scale' that is easy to install and maintain

January 2007 Sensors & Transducers

The new LM50SBR conveyor belt scanner from Laser Measurement uses completely different measuring principles from conventional belt weighing instruments. Instead of detecting the physical load on a conveyor belt (a value that is subject to variations due to changes in belt tension and wear) the non-contact, laser technology of the LM50SBR directly measures the volume of material flowing along the belt.

The volume flow (indicated in cubic metres per minute) is derived from the product of the average cross-sectional area of the material and the belt speed. The LM50SBR is able to measure both of these parameters without making contact with either the material or the belt giving the instrument immunity to spillage and other mechanical damage. The LM50SBR has four 4-20 mA outputs. They indicate the material flow, belt speed, cross-sectional area and cumulative total (totaliser).

The non-contact measuring principle of the LM50SBR simplifies the installation procedure. The instrument is mounted 1 m directly above the centre of the conveyor belt looking down onto the material. The laser scanner and its associated belt speed sensor make all the necessary measurements from this safe location. The instrument is completely self-contained, requiring only a 24 V d.c. power source. There is no external control box or complicated field wiring. This makes it possible to commission and configure the device without stopping the conveyor belt.

The LM50SBR has two external switch inputs. The first is an automatic 'belt zeroing' facility. This makes it easy to reset or recalibrate the zero load condition on the conveyor belt. The switch can be activated at any time while the belt is running and empty. The zeroing sequence takes about one minute. The second switch input resets the totaliser. Both switches can be activated locally, remotely or both options can be used simultaneously.

Whilst conventional belt scales can be used for both process control and accurate weighing for dispatch purposes, the LM50SBR is intended as a retro-fit instrument for basic control and inventory management. Its accuracy is limited to about ±3% on large belts but can worsen to ±10% on smaller belts. Also, the measurement taken is of material volume flow not mass. Multiplying the flow by the average density gives the mass.

For material storage and management it is often more useful to measure the flow (and hence the volume) of the material because this is not affected by moisture content. It is therefore possible to fill storage bins to their volume rated capacity rather than relying upon their approximate mass storage capacity which is directly affected by the material density.





Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

High-performance LineScan camera
Sensors & Transducers
Lynred, a global leader in infrared imaging technologies, has launched its next-generation SWIR LineScan camera and sensor, specifically designed for the inspection of silicon wafers, solar panels and waste management.

Read more...
Online monitoring solution optimises asset performance across
SKF South Africa Sensors & Transducers
SKF’s sales, service and management teams has joined forces to deliver an advanced, integrated online monitoring solution for a key customer in Tunisia, operating nine mines, five plants and eleven production lines.

Read more...
OMRON launches new non-contact
Sensors & Transducers
OMRON has unveiled its latest innovation in non-contact safety door switches, the D40A-2, which is designed to enhance workplace safety and streamline machinery operations.

Read more...
Vibration monitoring in three axes
ifm - South Africa Sensors & Transducers
Machine vibrations are important indicators when it comes to assessing the current condition of a machine. ifm’s new and smart IO-Link vibration sensor helps to implement a simple and scalable condition monitoring approach using but a single device.

Read more...
Smart solutions for weighing in hazardous milling zones
Sensors & Transducers
Minebea Intec supplies highly accurate weighing and inspection solutions that enable milling companies to organise their processes safely, efficiently and compliantly - even in hazardous areas.

Read more...
Optimise sludge treatment and reduce operational costs
Sensors & Transducers
The Endress+Hauser inline measuring devices, the Proline Teqwave MW 300 and the Proline Teqwave MW 500, determine the total solids content of wastewater directly through microwave transmission. This is considerably less time consuming than the process of determining total solids content in a laboratory.

Read more...
Family of analysers for smart and efficient chlorine measurement
ABB South Africa Sensors & Transducers
ABB has launched ChloroStar, a family of sensors, transmitters and accessories for accurate and reliable chlorine measurement and analysis that enable users in the water, wastewater and other industries to control chlorine more efficiently, enhancing treatment and increasing process uptime.

Read more...
Leading the way with Level 9 PDS implementation
Sensors & Transducers
Applying a Level 9 Proximity Detection System (PDS) to a mining operation is as much about changes in behaviour as it is about technical solutions, according to Pieter Wolfaardt from Apex, Booyco Electronics’ training partner of choice.

Read more...
Enhanced automated weld inspection system
Sensors & Transducers
SmartRay is offering the release of new hardware for its weld inspection system, JOSY, delivering elevated performance and flexibility in the process.

Read more...
Leaders in sensor technology
Gail Norton Instrumentation Sensors & Transducers
Photoelectric eyes have always needed perfect working conditions, but in the workplace there is no such thing. Steam, water, light and dirt interfere with most photoelectric eyes, but never with a Telco sensor.

Read more...









While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd | All Rights Reserved