Low Profile Load Cell Engineered For Success
A few years ago, we received an inquiry from a scale company wondering if we had an interest in going above and beyond what the market was offering in a low profile, high capacity vessel, hopper, tank weigh module that does not need assembly before installation.Download the PDF version.
The challenge consisted of a 50,000-pound capacity compression weigh module with a declared accuracy of 0.05 percent and the desired profile lower than 2.2 inches. This size would be about a quarter of what was common in a weigh module height of 8 inches. In the hopper and tank weighing sector of the process weighing industry, 0.1 percent is considered the high accuracy gold standard. Our Anyload engineers set out to improve the accuracy while remaining within the desired height constraint, or in this case, target. Shrinking a conventional weigh module envelope design was not going to cut it. The Anyload team first sampled a few existing competitive contenders and identified key vulnerable areas needing improvement. One competing product fulfilling the low-profile requirement had only achieved an accuracy of 0.3 percent; hence, short of the target. Another key issue was repeatability (because of movement) of the load cell due to temperature or loading conditions during the actual weighing.
With these challenges in mind and keeping with our Anyload design philosophy of delivering austere and reliable products, we developed our first prototype. Abandoning the spherical washer entirely, we internalized the applied force loading area with a spherical load pin. This allowed us to seal off the bottom of the load cell with a threaded and welded stainless steel ring, plus a rubber O-ring, thus improving the product’s reliability for washdown applications and keeping the uplift protection up to 50 percent of the capacity. Accuracy was much improved, even when there was a slight shift in the weight distribution or tilt to three degrees. However, this design still faced the same challenge of achieving higher accuracy— although to a lesser degree. A fundamental weakness of our spherical load pin-load prototype (and that of our fellow manufacturer with their spherical washer load cell) was that any off-center load movement would still interfere with repeatability during weighing. It’s the shifting of the point-of-contact in the load introduction area that causes the interference. Variable loading conditions and temperature variations made this challenge unavoidable. Our initial prototype did not solve the problem of horizontal movement, which lead to poor repeatability. We decided to abandon this spherical load pin approach in favor of a more novel approach and design. We flattened the top of the load pin. We implemented a protruding convex dimple with a concentrated radius centered on the load cell’s underside as the ideally focused load introduction area. Now, even with off-center applied loads, this elegant mechanical feature will better isolate the applied load to accommodate and provide a substantially more accurate reading. This design also reduced the overall size of the concentrated loading area, thus pinpointing precision. While our standard commercial model is promoted as having 0.1 percent accuracy, our extensive testing has found that this design is capable of 0.05 percent accuracy. At 50,000 pound capacity, we came below the ceiling of 2.2 inches with a total height of 2.09 inches. The Anyload solution has significantly improved accuracy and repeatability—all in all; it simply works better.
In two years of development, all of the capacities were created, and most of them are in stock at both our New Jersey and Vancouver warehouses, from 1,000 pounds to 200,000 pounds. For example, the total height of a 100,000-pound cell is 3.07 inches. Also, for ease of installation, we offer a top plate option for the weigh module. This provides a symmetrical bolt mounting pattern for the top and bottom. We rely on our customers and fellow competitors to provide the impetus for new products and improved designs. Rising to meet the challenge requires mutual inspiration and open minds. Our Anyload engineering team looks forward to continuing our industry-leading pioneering and forward-thinking. Patent pending for Europe and the USA.
Help Optimizing Water Efficiency In Stressed Climates
To reduce the environmental impact of commercial agriculture it’s important to look at the efficiency of water consumption and how that can improve the growing process. Agriculture is the largest consumer of water in the world today, but the efficiency rate of how that water is used is generally very low. Only a fraction of the total water usage is directly utilized for plant growth. The rest of it drains off or is lost through evaporation. When water is used effectively and responsibly, production quality and crop yield are positively affected. Increased water efficiency often provides benefits that go far beyond reduced water use. In an era where water consumption is rising and freshwater availability is increasingly limited—efficient water management in agriculture is essential to maintaining long-term sustainability for farmers as well as consumers.
Among the world leaders of agricultural technology a university team has been working on a research project to measure and optimize plant performance according to efficient water consumption. The results of this research will be invaluable to regions around the world that are under increasing water stresses. At the university’s agricultural campus, world renowned experts in plant stress physiology, soil and water science aim to secure future food production no matter what challenges climate change might bring. Their goal is to develop optimal processes and technologies to improve crop yield by developing strains more resistant to environmental stresses. A greenhouse containing potted plants is artificially cooled during the day by humidified air. Each plant needs to be monitored individually and continuously for their water consumption during growth. This is done by measuring the weight of the plants to deduce levels of water consumption in ambient conditions. To obtain research data, they require a sensitive measurement system solution that can provide precise, accurate, and reliable stream of information unaffected by temperature noise. This system is expected to save costs by reducing water and fertilizer needed while optimizing nutrient delivery, boosting yield by improving monitoring plant productivity and early stress detection. All these factors will help shorten time to market by improving plant screening effectiveness.
To accurately track very minute changes in weight of individual samples over a long period of time continuously. The tare weight of the plant containers are approximately 30kg, while the changes to the weight from moisture fluctuations only vary by a few grams over many hours and days. Therefore, the load cell must account for creep over time, even by a few grams as such small changes could compromise entire datasets. This must all be performed in a green house environment where the temperature fluctuates dramatically between 59-104ºF (15 – 40ºc), and while the high humidity may threaten to compromise the body circuitry of the load cell over its service lifetime.
Anyload’s 108TA OIML C5 load cells, with temperature compensation tailored specifically for the greenhouse climate to provide an even greater degree of accuracy than OIML standard C3 of 14-104ºF (-10-40ºc). Anyload is passionate about providing custom weighing solutions for any application. We are committed to delivering the best product for the job, eager to rise to any challenge.
Weighing a Production Platform
To Prepare a Gas Production Platform for Transport by Ship Across Ocean:The platform would be loaded on to a heavy lift ship at a seaport using dollies with dozens of rubber tires to move it. The rubber-tired dollies will need to distribute the weight over their total number. The heavy lift ship will have to add ballast to get the wide, open, after-deck down to the level of the load-out dock. Then, as the dollies roll the massive weight of the platform aboard, ballast water will have to be pumped, out of the ship, in an amount that equals the weight of that part of the platform that is already aboard. This is a delicate operation designed by specialized engineers who calculate the weight on the dollies, the weight of the volume of ballast water and the timing of the pumping that will maintain a level load-out between the pier and the ship..
The platform was actually built in two sections that would eventually be placed onto the legs on land. This is the kind of thing that engineers love and it is a fairly straightforward task. They need only get the weight of the platform and then calculate the amount of water to be removed from the ship as it rolls on board.But it is more complex than that. The platform had been built from plans that gave it about two dozen short legs that were designed to mate with a prepared site thousands of kilometers away in a different country. Rubber-tired dollies would support each of these stubby platform legs, but they did not have the platform’s weight equally distributed to each one of them.It was not a matter of simply weighing the whole structure and dividing by the number of legs. The bearing weight near each leg would have to be known to the engineers and this weight could only be accurately measured if each leg-area was lifted and weighted at the same time.
To lift the total platform as though on its legs all at the same time and get a weight of the pressure near each leg.A well designed and built load cells that could be placed between the hydraulic lifting jacks and the structural beams adjacent to the legs.Simple handles were affixed to each side for ease of manual lifting. Also on each disk load cell, there are two connectors, one each side of a junction box on the load cell body, each connector has one independent strain gage bridge. These strain gauges have been calibrated with the indicator individually, so in case of one load cell bridge failing on site, the second strain gage bridge will still provide the data.With the weight on each of the legs is determined, engineers responsible for the load-out to the heavy lift ship are able to determine the arrangement of the dollies and, most importantly, a schedule for the de-ballasting of the heavy lifts ship. The all-important information would also be used again at the other end of the voyage for the off load of the platform and when the individual legs would mate with the prepared site.
Anyload developed a unique load cell specifically for this project. The load cells are designed and built a series of circular disk load cells that could be placed between the hydraulic lifting jacks and the structural beams adjacent to the legs.It was a challenge to design the right load cell for this complex task. But it is the kind of challenge that is welcomed by the engineers at Anyload. Having been successfully completed, it is one more project in Anyload’s growing list of quality load cells for any application from milligrams to tons.
China’s First Retractable Stadium Roof
In 2005, we were contracted by Enerpac to manufacture and supply 96 load pins for Nantong Stadium, China’s first retractable stadium roof located in the Nantong, Jiangsu, China. Completed in 2010, Nantong Stadium is a multi-purpose stadium that holds 32,244 spectators and is known for being the world’s first stadium in which the propulsion and stabilisation of the moveable parts take place hydraulically.
• Materials: Stainless steel and alloy steel
• Capacities supplied: 10t and 150t
• Safe Overload: 150%
• Breaking Overload: 400%
Split Type Donut Load Cell
Designed to measure and monitor the tension force of an anchor that reinforces the stability of slopes for the prevention of landslides.
Each load cell half was designed with an individual strain gage and individual cable. When installed, the cable from each of the load cell halves are connected with a junction box.
The overall accuracy level achieved was 3% with a 0.5% difference in sensitivity when the load cell was rotated and used in different positions..
• Material: Alloy steel
• Capacity: 50t
• Safe Overload: 150%
• Breaking Overload: 300%
