Some customers have tried to use ultrasonic level transmitters, mechanical ‘yo-yo’s’ and load cells with limited success when measuring plastic pellets or flakes. Radar level sensors are also not suitable, because the dielectric constant of the material is too low.
Storage bins that are relatively small in diameter (3-10 metres) and tall in height present a problem for ultrasonic level transmitters, because the wide angle beam echoes off of the silo walls and gives false signals. Additionally, the material fills and empties with a significant angle of repose and the ultrasonic energy can be reflected away, instead of back to the receiver.
Mechanical ‘yo-yo’ devices have high maintenance requirements and many users have a problem with the plastic pellets covering the weight at the end of the cable and breaking it on retraction. In fact, customers can get an acceptable payback in maintenance savings alone by replacing the ‘yo-yo’ devices. Load cells have a very high first cost and high maintenance/calibration costs. Nucleonic level sensors can provide a reliable level reading, but these tend to be expensive and contain an undesirable gamma radiation source.
The LM80 provides superior performance at a competitive price because it has a narrow beam divergence (no false echoes off of tank wall) and will measure off of the steep angle of repose.
Recommendations when installing the LM80 on plastics silos include:
• Use the P801 dust tube option. Purging with instrument air is not generally required, but on about 5% of applications the static build-up is so bad that the dust tubes must be purged to keep dust from collecting on the lens. This problem seems to be most prevalent when the LM80 is located close to the fill chute.
• Use a metal mounting plate or flange and make sure it is grounded to the silo. This is usually accomplished by proper bolting and helps dissipate the static charge build-up.
• Use lightning protection: the lasers are typically installed on the top of a tall silo out in the open and can act as a lightning rod. Contact the service department for recommended protection.
• Use the Heavy Dust setting to ignore dust and fines that are suspended in the silo and to ignore feed falling in front of the laser.
The LM80 was successfully demonstrated at one plastic manufacturer’s site where it was purchased for an extended trial. There are over 200 silos at this site alone – plastics are a major potential market for laser level measurement devices.
Women shaping engineering at ABB ABB South Africa
News
Two ABB engineers share how curiosity, mentorship and an inclusive culture have shaped their careers, and what they see as the most exciting opportunities for women in engineering across Africa.
Read more...VEGA leads Africa’s next mining era VEGA Controls SA
Level Measurement & Control
Africa’s mines demand instrumentation that performs under extreme conditions, and VEGA’s level, pressure, point-level and density solutions are engineered to deliver exactly that. From flotation circuits to tailings management, its technologies help operations convert reliable process data into measurable gains in productivity, safety and control.
Read more...Inductive ring sensors monitor material flow in feeding technology ifm - South Africa
Level Measurement & Control
Inductive ring sensors detect metallic parts moving through tubes at up to 35 m/s, whatever their size, enabling precise counting, flow control and reliable detection of blockages or misfeeds.
Read more...Groundwater level measurement using LoRa module Instrotech
Level Measurement & Control
Monitoring groundwater levels across large industrial sites is critical. Salzgitter Digital Solution was tasked with developing a fully automated and digital monitoring system using Long Range Wide Area Network technology.
Read more...Where corrosion meets control VEGA Controls SA
Level Measurement & Control
Reliable level measurement is essential in copper and cobalt processing, and at KCC, VEGA Controls is helping ensure uninterrupted operations with robust vibrating level switch technology.
Read more...Safety, hygiene and quality management for Africa’s pharmaceutical manufacturing industry VEGA Controls SA
Level Measurement & Control
VEGA sensors support critical processes in pharmaceutical manufacturing such as fermentation, purification, formulation, filling, storage and CIP/SIP cleaning cycles. Their design ensures that pharmaceutical manufacturers can maintain sterility, reduce downtime and achieve consistent batch quality, even in demanding production environments.
Read more...Level measurement for hygienic applications Endress+Hauser South Africa
Level Measurement & Control
Endress+Hauser’s Liquiphant is considered to be the most reliable and safe point level detector in industrial plants. The latest generation of devices is ready for Industry 4.0 and, with the Liquiphant FTL63, is ideally suited for applications with hygienic requirements.
Read more...Smart power solutions for a low-carbon future ABB South Africa
Electrical Power & Protection
As the world marked Earth Day 2026, ABB is highlighting the role of low-voltage smart power solutions in improving energy efficiency, reducing emissions and enabling more sustainable infrastructure.
Read more...Level measurement of an acid dosing tank at a WWTP
Level Measurement & Control
Ferric chloride and other acids are essential chemical substances in water and wastewater treatment. To control the dosing of acid solutions, an Australian wastewater treatment plant uses a special container to store, mix and add these chemicals. The company opted in favour of KROHNE’s OPTIWAVE 1540 radar level transmitter
Read more...DCS for maximum plant efficiency and reliability ABB South Africa
PLCs, DCSs & Controllers
ABB has introduced SPR2025, the latest Symphony Plus DCS package release to enable modernisation and efficient performance for the process and power industries.
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.
printer friendly version