All of these applications require significantly large load cells, often ones that are custom-made and not in stock:
For instance, in mine shafts, the weight on the coal seam roof is constantly monitored by a high-capacity, heavy-duty load cell that can alert miners if there’s the danger of a roof collapse. The coal seam is excavated in a specific engineered pattern that keeps roughly 50 percent of the coal in a place that supports the roof of the area that is being actively mined.
High-capacity load cells can also be utilized to observe running loads as well as the weight on the bridges. These types of systems usually measure weight allocation, which permits measures to be executed to protect the structure of the bridge as well as drivers.
Rockets use load cells to surveil the thrust force that is pushing the airframe of the rocket. Upright takeoffs from the Earth’s surface demand a thrust force that is anywhere from 30 to 50 percent more than the rocket’s weight and payload, which can create significant strain on the rocket’s frame. By keeping an eye on actual loads instead of calculated load, the airframe design of the rocket can be fine tuned.
What Are the Essential Design Considerations When High-Capacity Load Cells Are Produced for Large Load Systems?
For starters, high-capacity cells tend to be integrated into systems, machines, or structures with very little space for the sensor to be installed. For that reason, heavy-duty cells need to be designed so that they are small, lightweight, and compact with regard to their overall capacity. Measurement Specialists has planned and constructed high-capacity cells as little as one inch in height and six inches wide.
Another key benefit of these dense load cell designs is that they’re more affordable and are much easier to produce, assemble and incorporate into various load-monitoring systems. The geometry also plays a huge role. As a general rule, the tank, bridge, and other equipment where force needs to be measured has been manufactured and installed previously. In order to install a high-capacity cell, a retrofit is necessary. Similar to a jigsaw puzzle piece, the geometry of a high-capacity load cell requires that it fit perfectly into the equipment or structure it’s monitoring. The supplier of the load cell must be able to design the cell’s overall geometry to the necessary shape so it can be integrated into the current equipment. This could necessitate machining the load cell’s geometry to be circular, rectangular, square, or some other shape so that it fits the necessary space available.
Last, but not least, many systems in the aforementioned application list are unable to properly and safely function without examining the forces that they are subjected to. Appropriate design, manufacture, as well as the deliverance of the correct capacity cell are crucial to the project’s success. At Measurement Specialists, our manufacturing operation allows us to distribute custom-made load cells with capacities of more than one million pounds in four weeks or earlier—something that most companies are unable to do.
In regard to the delivery and installation of large scale load cells, it somewhat depends on the pace that the load cells are able to be calibrated to NIST traceable standards. There are only a few locations with these standards that can calibrate high-capacity load cells to one million pounds or higher. We have long-standing relations with large-scale testing facilities, which along with our in-house capabilities allow us to rush NIST calibrations for our custom load cells. All loads need to be calculated precisely to ensure structural integrity and safety. With the highest accuracy requirements and limited availability of capacities of one million pounds and more, accuracy needs to be within 0.25 percent of full scale.
High-capacity load cells tend to be used for control and/or monitoring. Preferably, the output of these cells will match the current instrumentation and equipment. Load cells can be planned and fabricated in order to offer the preferred output so that the cells can be interfaced to any data acquisition applications, controller, instrumentation, or visual display equipment that is currently in use. At full scale, you can expect outputs of between 1.5 and 3 mV/V. On the other hand, it is possible to incorporate signal conditioning to allow high level output signals of 0 to 5 VDC, 0 to 10 VDC, or 4 to 20mA.
It is possible to design high-capacity load cells to function in intense environmental circumstances like corrosive environments, heat and cold, as well as underwater.
If you need a large scale or high-capacity load cell developed, work with a supplier like Measurement Specialists that can offer custom-made cells. We have wide-ranging experience in the design, manufacturing, and calibration of large-scale and high-capacity load cells that can withstand weight of more than one million pounds. If you would like to learn more, get in touch with one of Measurement Specialists’s specialists today.