Ecoustic board grader FAQs

The Ecoustic™ Grader is a fully automated structural timber grading system that determines the stiffness (MoE) of boards by combining density and acoustic wave velocity. The system is a turn key solution requiring virtually no operator assistance and has minimal maintenance requirements.

Density is determined by the combination of volume and weight. A non-contact laser measurement system is used to measure the width, thickness and length of each board. Weight is measured dynamically by a load cell weighbridge system.

Acoustic Wave Velocity (AWV) is measured by striking the board with a pneumatically controlled hammer which initiates a stress wave impulse into the board. The acoustic response from the impulse is measured using a microphone and the signal is processed to determine the boards' longitudinal AWV.

Information from all the measurements is combined and processed to determine the boards' stiffness (MoE). The board is then assigned a grade based on the thresholds set within the Ecoustic™ Grader software. The grade can be marked and identified by a coloured spray mark on the end of the board.

Yes, the Ecoustic™ Grader can output information via serial, Ethernet and digital communication to other mill equipment such as bin sorters, printers etc.

The system is controlled by National Instruments hardware and Labview software. This gives us the ability to precisely control the system and enables a friendly user interface via a PC for additional functionality.

The Ecoustic™ Grader can operate at up to speeds of 140 boards per minute but maximum speed is dependant on individual mill set up.

Overall accuracy will depend on a number of factors including board measurement accuracy, weighbridge accuracy and the general condition of the timber line.

Thickness is measured using 2 opposing head ScanMeg Ultra S single point lasers using a 1200Hz scan rate. The Ultra S lasers provide a resolution of ±0.1mm with measurement ranges selectable from 0-150mm or 0-300mm and a typical accuracy of ±0.2mm.

Width is measured by combining the digital signals given from the upper thickness measuring single point laser and the Ecoustic™ Graders' encoder board tracking system. Width is measured at the same point and time as the thickness. The resolution of the width measurement system is typically 0.01mm with its accuracy being limited to the boards' smoothness of travel through the laser heads and mechanical vibrations of the chain strands. The width measurement range is from 5-500mm with a typical accuracy of ±3mm.

A ScanMeg HD scanner is an available option which will mitigate uneven timber travel speed and excessive vibration for a more accurate width measurement. The performance of this scanner is unparalleled utilising a 1 kHz scan rate producing a resolution of 1mm and a typical accuracy of ±1mm.

Length is measured using a Sick DT50 single point long range laser head. The laser head provides a resolution of 1mm with an accuracy of better than ±7mm. It is possible to position multiple laser heads to accommodate bowed or curved boards.

Weight is measured as the board travels within its lug across a load cell weigh bridge system. The weigh bridge consists of a load cell assembly positioned along each strand and in parallel to each other. The load cells are extremely accurate providing a typical weigh bridge resolution of 20g and an accuracy of ±50g during calibration. The dynamic accuracy is typically better than ±10% of the boards' weight in the green mill and ±4% in the dry mill per board basis.

Data is recorded and stored for every board that passes the grader, including all dimensions, weight, density, MoE and assigned grade as well as all the settings and parameters used to grade the board. The date and time are also recorded.

All of this information can be automatically uploaded from the grader to our web based database system. Specific searches can be conducted to view, analyse and report the data from any computer connected to the internet.

The Ecoustic™ Grader has a small footprint and can be fitted to most lugged chain strands. It requires a minimum of 1.3 meters of chain space to be installed. The only other space required is for the control hardware and computer which is housed in a stand alone PC cabinet measuring 600m x 600mm x 1800mm high.

The Ecoustic™ hammer unit requires a common timber line that should not deviate by more than 5mm and boards must be trimmed at both ends prior to being measured and struck. Other requirements relating to the chain are that it should be lugged and in good functional condition and the less vibration the better. We sometimes may need to stiffen up the section of chain where the grader is to be installed. The Ecoustic™ Grader requires a 240V, 10A power supply and a 3/8' supply line of clean air. It is recommended that a broadband Ethernet connection be supplied to the Graders' computer in order to get the most from the system as well as enable technical support.

Typically installation of the hardware will take about 3-4 days with commissioning, tuning and training taking another 3-4 days.

We provide a 12 month warranty as well as a maintenance service plan to ensure reliable trouble free performance. With an internet connection to the grader we can gain access to the system and can trouble shoot most problems remotely.

There are numerous benefits to be had from installing an Ecoustic™ Grader. One of the major benefits is that it can be installed in the green mill and can grade boards for stiffness early in the production process which will avoid unnecessarily processing (kiln drying and planning) low stiffness out of grade boards. This saves costs and increases efficiency and productivity. Other benefits include: fast grading speeds, small footprint, quick and easy installation, low maintenance, no operator, and instant access to information on every board that passes the grader.

Direct cost savings can be made by not processing low stiffness out of grade boards through the kiln and planner, as they can be sent to alternative uses in the green sawn condition. The other way that increased profits are made is from the freed up capacity available for processing in grade profitable boards.

There are a number of factors that will contribute to your return on investment such as how much downgrade you currently produce, your total production volumes, and the market prices you can achieve for your products. Generally speaking our equipment shows a very fast payback. In most cases payback is achieved within 3 - 12 months but some mills have shown even quicker returns. We have developed a calculator where we can enter your information and give you an indication of the potential payback for your specific situation. Please contact us for a free assessment.