High accuracy, single idler,
full floating belt scale frame

Technopark Automation & Control belt scales are designed to suit every user application. Our belt scales are used in South Africa and abroad in industrial, mining, chemical and food manufacturing industries.

We use both a single idler as well as a three idler design. The single idler is used in medium accuracy requirement and the three idler in high accuracy applications.

Apart from belt scales we also manufacture belt weigh feeders, volumetric feeders and loss in weight feeders. We also supply special configurations for dynamic weighing, depending on client requirements.

Principle of operation

Typical multi idler
belt scale installation

The principle of operation of an electromechanical belt scale is to measure the belt loading and belt speed and then compute the throughput rate, normally in tons/hour. This information is then used to control the feed rate of a process and/or reflect the throughput rate of a particular section of the plant. The scale feed rate and totalizer values are available over a serial communications port which can be used for management reporting purposes.

For best results precision balanced idlers should be used throughout the scale area. With careful alignment of the idlers, measurement error forces are minimized.

Belt scale calibration

Conveyor belt scales are normally calibrated in three steps:

  • 1. Determine the speed pulse count over a multiple number of belt revolutions.
  • 2. Establish the average belt zero over the same number of completed belt revolutions.
  • 3. Place a test weight or similar on the scale and integrate the totalized value over the same number of completed belt revolutions. A correction is then fed back into the system on completion of the test.

Our belt scales are easy to install and calibrate through the use of its user friendly calibration and diagnostic programs.

Calibration weights are used for the initial scale calibration after which a material bulk test is performed for fine tuning. Belt scale zero and span calibration should be checked once a month.

A combination of a highly sensitive load cell arrangement and digital speed sensor is used by the belt scale integrator to compute instantaneous feed rate, totalized value and belt speed. This information is then passed through a programmable filter for optimum performance.

Belt scale installation

It is important to make the correct decision as to where to install the belt scale on the conveyor belt. Factors like belt tension variation, vibration and accurate belt alignment are some of the important issues to take into consideration.

Interfacing the belt scale to the plant monitoring and control system is available through standard 24 V d.c. pulse and 4 - 20 mA current outputs. Various serial communications options are also available. This makes it easy to communicate with plant PC'S, SCADA systems and PLC'S.

Technopark Automation & Control offers turnkey installation, commissioning, testing and trouble shoot services. You are welcome to consult with us on your present and future requirements.