Load cells are of great and fundamental importance in the field of highly modern and efficient weighing technology. Are you looking for a weigh module that meets your needs and requirements? Not an easy task given the variety of load cells available. However, you are now one step closer to making a well-founded decision. Our product range covers a wide variety of applications and production processes.
Customized solutions for your system
Whether modules for use with containers in the low kilogram range or systems with hundreds of tons - we have the right solution for your company. We offer a wide range of installation modules for mixers, agitator tanks, large outdoor silos and mobile systems. We not only take care of professional installation and commissioning, but are also a competent partner for TÜV certification and custody transfer approval of any load cell modules.
Weighing technology: innovation in practice
Load cells play a central role in state-of-the-art measurement technology and high-performance weighing technology. But what is actually behind these measuring modules? In technical jargon, these complex precision components are known as force sensors or force transducers. They are used as a mechanical functional element in a variety of different weighing devices. Professional calibration enables reliable measurement results regardless of the dynamics and load class. Common parameters are grams (g) and kilograms (kg), as well as metric tons (t). As a rule, load cells are based on a spring body. When a load is applied, an elastic deformation is generated, which is converted into an electrical signal via so-called strain gauges and thus controls the functionality of the scale. Depending on the load class, different spring body designs are used.
Optimize and standardize
The exceptional measurement spectrum lies between 100 grams and 1000 tons. Alternative measuring methods also cover results in the low gram range. Calibration is a key classification feature for load cells. Uniform calibration and official testing is required by law for legal-for-trade scales. This is intended to optimize and standardize the margin of error. Innovative load cells enable effectiveness and efficiency close to the optimum - for modern production processes in the field of silo technology and bulk materials. Are you interested in the data sheets of various load cells? You can find technical and other details in our product brochure. You are also welcome to request a quotation at any time: Request a quote Load Cells. We are sure to have the right solution for your requirements.
Safemount load cell up to 150t
The economical solution for larger silos, tanks and mixers in the range between 5 and 150 tons: The reliable and maintenance-free Safemount module ensures the control and optimization of production processes and is also largely resistant to vibration, dust, moisture and corrosion.
Cleanmount load cell up to 10t
The clean solution for tanks and dosing containers from 250 to 2,500 kilograms: The Cleanmount module is predestined for use in the chemical industry and pharmaceutical production processes. All components of the robust stainless steel construction are also easy to clean.
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TLC 95 load cell up to 10t
The high-precision solution especially for agitator tanks weighing between 1,000 and 5,000 kilograms: the integrated tension load cell of the TLC 95 weighing module reliably compensates for lateral forces and any vibrations, thus ensuring optimum dosing accuracy and zero-point stability.
Tension load load cells up to 25t
The reliable solution for crane loads between 100 kilograms and 25 tons: Tensile load cells with integrated pendulum protection are predestined for precise content measurement of suspended containers and rotating production components such as conveyor belts or screw conveyors.
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Loadpin up to 500t
The tailor-made solution for crane loads and hoists in the 250 kilogram and 500 ton range: Each load pin is individually manufactured according to customer specifications, whereby even special designs with an electronic interface are possible. Proven applications include tilting furnaces with liquid aluminum.
The most important selection criteria for your load cell
You know your silos and tanks best. But do you also recognize their potential? If you want to know how much is really in your containers and production, there is no way around a load cell. However, given the wide variety of designs, the choice is often a real challenge. With our practical guide, we would like to help you find the right solution for your requirements and demands. Strain gauges, bending and shear bars, single point, ring torsion and cylindrical load cells, S-Beam or strain gauge sensors - the range of high-precision weighing technology is overwhelming. It can be difficult to maintain an overview. Decisions need to be made when searching for the optimum load cell for a specific application.
The following factors are decisive:
- Which type of measuring cell is best suited?
- Which ambient conditions are characteristic for production?
- What is the total capacity of the container in question?
We would like to take a closer look at these key points below.
A systematic approach to the right module
Consider the three questions as pillars of your final decision and find a solid basis. After all, you don't just want to find a high-quality load cell, but the optimum weighing module for your application.
Measuring cell type
Both compression load cells and tension load cells impress with their outstanding measuring accuracy. But where exactly is the focus? For point loads of up to 5,000 kilograms, tension load cells are the simple and cost-effective option. The stabilization of suspended loads is largely automatic and the thermal expansion of any containers is minimal. Measuring cells of this type are predestined for use with inner containers integrated into steel structures. Pressure load cells, on the other hand, are the logical alternative for stationary containers on concrete foundations or comparable fixings. Depending on the respective design, distribution to several load points is possible or even necessary. Various approaches can be considered: while three-point installations are relatively unproblematic in terms of load distribution and leveling, four-point installations offer around 22 percent more stability, especially for outdoor silos. The acquisition costs of an additional load cell are usually lower than the additional financial outlay required to reinforce a three-point construction. For square or rectangular containers, a four-point installation should always be implemented. Even if the greater the number of load points, the greater the effort required for alignment and leveling during commissioning, it is important to be consistent with the number of load cells. For example, a maximum of 75 percent of the nominal load should be calculated per load cell for outdoor containers. The respective load share results from the quotient of the total weight of the construction including contents and the number of load points. As the load distribution can vary due to external influences such as wind load or seismic forces as well as characteristic construction features of the container and the overall structure, it is essential to have a structural engineer check this.
Load cell: Ambient conditions
Here too, various factors come together to influence the choice of load cell and mounting module. Basically, the stress on the technology can be divided into two areas:
- Environmental influences such as humidity, heat and chemical reactions.
- Mechanical factors such as statics and dynamics.
Contamination from dust, corrosion in conjunction with chemicals and salt water, but also vibration, can have a decisive influence on measurement results and considerably shorten any maintenance intervals. The intensity and duration of the load also have an influence on running performance and precision. In the area of CIP cleaning, a load cell with protection class IP67 or IP68 is almost without alternative. In manufacturing processes with aggressive chemicals, attention must be paid to the resistance of the load cell itself as well as that of the installation modules and junction boxes. For example, installation modules and alignment must be designed to withstand the thermal expansion of containers. An incorrectly aligned installation module can not only lead to significant measurement errors, but can also cause irreparable damage to the weight sensor. In addition, potential falsification of measured values and wear due to corrosion, leakage currents or extreme temperatures should also be considered. Without spare modules, any subsequent costs can quickly rise to unimaginable proportions.
Total capacity of the load cell
As weighing sensors are generally designed for a defined load range, the total capacity of the container is of crucial importance when selecting the right load cell. Depending on the load range, a different measuring principle comes into question. The differences between bending, shear, compression and other methods are explained in detail in the following section. As a general rule, more load cells do not always mean higher acquisition costs. As the module price increases exponentially above 50 tons, it is sometimes more economical to install more load cells with a lower load range.
Comparison of different measuring principles
Each load cell is based on a specific measuring principle. Each method has its strengths and weaknesses. But which principle is suitable for which application? We take a closer look at the most important ones:
Bending
Bending rods are a reliable option for precise weight measurement of low load levels in the range between 2 and 500 kilograms. For symmetrical containers, suspension via tension ropes including centering cone is recommended for uniform, vertical force transmission. Application-specific installation modules with overload protection and elastomer bearings significantly optimize load control. Vibrations and shock loads are thus damped in the best possible way and any lateral forces also have minimal influence on the measurement results.
Shear
Simple shear bars are available for measuring ranges between 500 kilograms and 20 tons. This user-friendly method impresses with its high precision and resistance to lateral forces. For medium to high capacity silos, so-called double shear bars with integrated restraint are generally used. The combination of two shear bars enables a comparatively large load range of between 3 and 200 tons despite the low overall height. Due to the central application of force, off-center loads are virtually not a factor in a load cell with a double shear beam.
The folded double shear beam is an alternative design and to a certain extent the exotic among load cells. The characteristic design allows dynamic influences to be optimally compensated. For this purpose, a mounting plate is fixed to the foundation and the base of the container. Due to the tensile load, the element automatically centers itself in the event of vibration, oscillation or lateral forces. The standard measuring range is between 2 and 20 tons.
Elongation
The cylindrical load cell is suitable for production environments with large-capacity silos and capacities of up to 500 tons. The measuring principle is based on a hollow cylindrical or segmented spring body, in which a certain minimum height ensures a homogeneous progression of the lines of force.
Compression
Strain gauges offer an uncomplicated and reliable approach for retrofitting existing silos and for the initial equipping of large silos in the 30 to 2,000 ton range. For this purpose, temperature-compensated strain gauge sensors are attached to the supporting structure of the silo using high-strength machine screws. The load-dependent compression in the material structure is recorded by the strain gauges and converted into a proportional voltage signal, which is standardized and read out by the downstream electronics. This maintenance-free method is predestined for the gravimetric inventory control of individual silo containers on supporting structures and floor-standing silos. With one or two sensors per support, the measuring accuracy varies between one percent on the inside and between two and three percent on the outside. During dosing and loading, maximum deviations of 0.2 percent of the net weight of the silo are to be expected. For fast loading processes of less than 20 minutes and a silo capacity of up to 500 tons, this corresponds to a tolerance of between 300 and 500 kilograms.
Advantages and disadvantages of individual designs at a glance
Based on the various measuring principles, here is a compact comparison of the different load cell types:
Pro
- low cost factor
- High precision
- Identical construction almost independent of the manufacturer
Contra
- Sensitivity to lateral forces and eccentric force application
Measuring deviation
0,03 %
Pro
- low overall height
- Wide range of applications
- high stability with lateral forces and shifting of the load point
Contra
- Stable base plate made of high-quality steel is essential
- High, defined torque required for fastening screws
Measuring deviation
< 0,03 %
Pro
- low acquisition costs
- simple installation
- Insensitive to lateral forces and thermal expansion
Cons
- Lack of calibration capability
Measuring deviation
< 0,05 %
Pro
- uncomplicated assembly
- High precision even with dynamic influences
- calibration capability
Cons
- Comparatively high overall height
Measuring deviation
0,02 %
Pro
- high stability
- large load ranges
Cons
- high assembly effort
- Sensitivity to eccentric force application
Measuring accuracy
0,05 %
Pro
- simple installation
- Easy retrofitting of existing silos
- Cost-effective option for large-capacity silos
- High reliability and maintenance-free
- Insensitivity to force shunts
Contra
- Limited measuring accuracy outdoors (due to thermal deformation)
Measurement deviation
With one to two sensors per support:
- 1 % of the maximum net content indoors
- In the outdoor area 2 - 3 % of the net content
When dosing and loading silos:
- less than 0.2 % of the net capacity
Conclusion
The selection of suitable weighing sensors depends on a large number of application-specific parameters. The respective production environment is just as important as the basic requirements and influencing factors with regard to the manufacturing process. In addition, precision is only as good as the combination: only the optimum interaction between container, load cell, weighing module and evaluation electronics guarantees the best possible system accuracy and reliability. With regard to design and installation, details such as the possibility of professional decoupling of pipelines, discharge units, ladders and platforms must be taken into account. In addition, the foundation and supporting structure must be designed for point loads and should yield uniformly by a maximum of ten millimetres. Planning errors with regard to the design can usually only be corrected after the installation of load cells at considerable expense. It is therefore advisable to consult a specialist in the field of weighing technology at an early stage of the planning phase. Competent and, above all, individual advice can make all the difference here.
