HBM has made the SP4 footprint an industry standard for platform load cells used throughout the industry. The uniform dimension of the load cells helps machine builders, scales and plant manufacturers remain flexible and to save time and costs during development. With the PW15iA, HBM now offers the world's first digital load cell with this "footprint." It is the latest member of a series with six HBM load cells in the SP4 footprint that optimally complement each other in their application—from simple weighing tasks to process automation.
"Shortening development times, simplifying installation, designing downwards, and remaining flexible in equipping weighing systems, the unit footprint of load cells offers machine and plant manufacturers fundamental advantages,"
says Thomas Langer, International Product Manager for Weighing Technology at HBM. "Based on the SP4 footprint, HBM has developed innovative products, setting a standard for platform weighing cells in the industry worldwide. With the PW15iA, the format now becomes digital. "A footprint describes the dimensions of a load cell that are decisive for the installation: the dimensions of the upper and lower stop surfaces, the height, the position and distances of the threads for the screw connection and the Gewinde sizes. Weighing cells with the same footprint can be replaced without any constructive adjustments. For example, weighing systems can be easily adapted to different requirements such as rated load, protection class and accuracy class.
A format for platform load cells has become particularly established in the industry over the past two decades: the SP4 footprint. Its dimensions are defined as follows: 150 mm long, 40 mm high and 25 mm wide, six M6 threaded holes for installation, and another M6 thread and fine thread for integrating an overload stop. HBM used the format for the first time for the load cell SP4M, which was presented by the metrology specialist in the early 1990s.
"It is one of the best-selling flat load cells on the market. The load cell is so successful that other manufacturers took over the dimensions of the SP4M — and continue to build on it today,"
says Thomas Langer. With the PW15iA from HBM, the successful format is now digital, making it easier to develop complex systems. Automated applications can be easily implemented with programmed functions, for example for checkweighing and for filling and dosing applications. If bottles in filling systems do not have the correct weight after filling, the load cell recognizes this automatically and now sends a digital signal directly to the sorting unit, which removes the defective bottle from production. The previous detour via the control unit is eliminated. This direct communication between the sensor and the actuator is much faster, thereby improving the throughput times and productivity of the systems. This consequently saves time and costs. In addition, the algorithms already stored in the load cell substantially reduce the development times. Parameterization of the PW15iA load cell is easily possible via the HBM PanelX software.
The new digital platform load cell eliminates the need for additional meter electronics, such as measuring amplifiers; further costs can be saved and less space in the control cabinet is required.
„The example of the PW15iA shows an additional advantage of the uniform footprint: Mechanical and plant engineers have the opportunity to introduce new technologies such as digital weighing in parallel with proven systems,"
explains Thomas Langer, "and without having to invest much time, money and effort in new developments, for example, of weighing systems." Existing systems and machine series can thus be easily retrofitted with digital technology; it is merely the replacement, for example, of the analog with a digital load cell, that is necessary.
PW15iA is the latest load cell in a successful evolution series of six HBM load cells in the SP4 footprint, which today optimally complement each other in their applications. Thanks to the uniform dimensions, manufacturers can choose the right load cell for their requirements and tailor their systems to the needs of their customers:
- The SP4M load cell, which gave its name to the SP4 footprint, is the cost-effective option: for example, for use in post and counter scales with nominal loads between 1 kg and 200 kg and its lightweight aluminum measuring body.
- Thanks to its corrosion-resistant steel measuring body, the PW15B platform load cell is suitable for applications in harsh, chemical industrial environments—for example, in areas where aggressive cleaning agents are used.
- Thanks to its hermetic encapsulation, the PW15AH flat load cell can withstand even more demanding conditions, such as high-pressure cleaning. With protection rating IP68 / 69K, it is permanently protected against moisture. For highest quality and reliability, HBM tests each cell for 100 hours at a water depth of one meter.
- The PW15PH , with its hermetic encapsulation and IP68 / IP69K protection, is also suitable for use in adverse environments. Equipped with a hermetically sealed device plug instead of a permanently installed cable, the load cell can be easily and flexibly installed and removed.
Constructed in an "easy-to-clean" design, PW25 fulfills hygienic guidelines, for example for applications in the food and beverage industry. With protection rating IP68 / 69K, it is optimally protected. Thanks to their round shape and electropolished surface, dust and dirt cannot adhere.
- The PW15iA is the digital version of the PW15PH. With its hermetic encapsulation and IP68 / 69K degree of protection, it combines the robustness of the load cell with the advantages of digital technology, such as lossless data transmission with CANopen, DeviceNet and RS485. With pre-programmed algorithms for checkweighers and filling applications as well as two digital inputs and outputs for the control of ejectors, vibrators and filling valves, the most demanding processes can be easily automated.
For machine and plant manufacturers, the uniform footprint brings another plus: Because the format of the SP4 footprint in the industry is used by many measurement technology manufacturers, they can simply upgrade their systems with the technology of HBM, the global technology leader in measurement technology.
"With our proven strain gauge technology, our load cells are world leaders in precision and temperature stability. And with products like the PW15iA, we're making the successful SP4 footprint with modern technology ready for the digital future,"
emphasizes Thomas Langer.
With modern digital technology and SP4 footprint, the PW15iA offers enormous advantages for machine, scale and plant engineers.
- Automate processes quickly and conveniently with digital I/Os and programmed functions for filling, dosing and checkweighing
- No additional measuring electronics such as measuring amplifiers necessary
- Lossless data transmission with digital measurement signal
- Faster and more productive plant processes thanks to direct sensor–actuator communication
- Easy digitization of analog weighing systems thanks to a uniform SP4 footprint;
- Convenient parameterization of the load cell with the intuitive HBM PanelX software
Compatibility with other HBM weighing components thanks to standard instruction set with FIT, PAD and AED
- Permanently protected against dust and moisture with hermetic encapsulation and IP68 / IP69K
Corrosion-resistant stainless steel body