The Evolution of Double-Ended Shear Beam Load Cell

Definition: Double-Ended Shear Beam Load Cell

The double-ended shear beam load cell is similar in design to the single-ended shear beam, but it’s secured at both ends while force is exerted on the center of the beam structure.

The primary use of a double-ended shear beam is to weigh heavy loads and it can serve heavy capacity applications over 5t to 100t with ultimate precision.

Its common applications include heavy hopper, tank scales, or truck scales. It makes measuring compressive forces easy and cost-effective.

The primary purpose of designing these load cells in this way is to accurately measure higher loads.

In the case of a double-ended shear beam load cell, the compressive force is introduced centrally.

As a result, it’s quite insensitive to lateral loads. The most important part of a double-ended shear beam load cell is its spring body.

It consists of a metal part deformed under the action of force and whose deformation is canceled when the action of the force is removed.

This deformation is registered by a strain gauge attached to the metal and converted into an electrical impulse.

As they’re mostly installed in industrial equipment, the load cells are designed in such a way that they are largely insensitive to external influences or versatile environmental conditions.

In general, they’ve protection classes IP67 or IP68. The selection of the right double-ended shear beam load cell is determined by the following:

• The nominal load
• The breaking or limit load
• Minimum division value

A double-ended shear beam load cell has two spring bodies and is calibrated in grams, kilograms, or tons.

Double-ended shear beam load cells are mainly found in industrial scales for high loads in the range of several tons.

Several cells can be connected in parallel without any effort since load cells are mostly impedance trimmed (output current calibrated).

The Selection Criteria of the Double-Ended Shear Beam Load Cell

The key to successfully completing every process is having the right tools and equipment.

It’s important to understand your needs, environment, and goals to select the right hardware for your applications to achieve ideal performance and accuracy.

Obtaining high-quality, reliable, and accurate readings is critical for weighing equipment especially for load cells.

However, industrial load cell designs accommodate many different tasks, sizes, durability, orientations, signal outputs, and environmental factors.

The following criteria is the key to finding the perfect double-ended shear beam load cell for your applications and industrial weighing equipment.

1. Consider the Load Input Direction

The principal load cells work on is to convert the energy of an applied force into a quantifiable electrical signal and that’s also a primary use of double-ended shear beam load cell.

The strength of the signal is proportional to the force. In a perfect environment under ideal conditions, the perfect weighing is possible and therefore required the right load cell that can adopt that particular environment.

There can be many irregularities and uncontrollable factors in load measuring and your load cell must be capable of handling the unexpected conditions.

At CUBLiFT, our highly skilled staff of engineers consider the physical principle of materials “stress” when designing a double-ended shear beam load cell.

A physical system can undergo and the orientation of the load influence the design of the various load cells by knowing the type of stress it’s experiencing.

• Normal Stress and Normal Loading:

Normal stress took place when the applied force is perpendicular to a defined surface or plane. It’s known to be the simplest type of stress to calculate applied force or weight.

Normal stress can be either compressive or tensile. Tensile forces stretch or pull the body, while compressive forces squeeze the body.

• Bending:

Bending is when an external force applied to a load cell causes it to bend and record measurements based on its reaction.

• Shear Stress:

A stress component that acts in the considered plane is known as shear stress. It’s much like a sheet of paper between two opposing blades of scissors.

The point where the opposing blades meet and cause the paper to shear into two parts is known to be the point of maximum shear.

• Torsion:

It occurs when an applied external force causes the structural body of a load cell to twist.

Load cells with torsion force measuring is very important to weigh rotating or spinning objects that mostly experience it.

2. Consider the Object to be Weighed: Capacity, Resolution, Shape

Every weighted object determines both divisions required of the load cell, its resolution, and the rated capacity of a load cell.

All of these things determine the desired load cell class. The minimum and maximum weight of the object is not the only thing important to select the right load cell for your application, but the desired resolution or smallest weight difference that must be measured.

Most importantly, always go for the load cell that satisfies the following statement:

A load cell whose shape, mounting, and capacities accommodate the shape, maximum and minimum weights, and smallest weight variances of the measured object.

3. Consider the Operating Environment of the Load Cell

Many environmental factors affect the operation and performance of a load cell, and therefore affect its selection process.

Selecting the right material, type of IP or weight capacity rating of a load cell defines its performance and must be according to the following.

1. Moisture: It’s one of the most damaging environmental conditions for a load cell. It can cause corrosion to load cell material, short circuits in its electronics, and other failures. Every load cell must be corrosion-resistant.

1. Chemical Exposure: Like moisture intrusion, chemical exposure can cause corrosion to the load cell material. In case your environment has exposure to chemicals, required load cells with chemical-resistant properties.

• Temperature: Temperature can make a huge difference in the operation of a strain gauge load cell since the load cell employs resistive elements and temperature affects electrical resistance.

A load cell must function perfectly within temperature extremes the load cell will be exposed to and a system designer must ensure that.

1. Vibration and Wind: Vibrations can be caused by seismic activities, heavy traffic, or industrial activities that can artificially add loads to a load cell. Likewise, something that can add more force to the intended load direction of a load cell is lateral forces.

What should be high enough of a load cell is its rated capacity that the maximum load plus potential added environmental loads do not exceed this limit.

4. Consider the Desired Accuracy, Error Ratings, and Ease of Calibration

In the end, once the material, design, IP rating, and load cell class are understood and defined, you must consider factors such as the following to make the final decision:

• Combined error
• Hysteresis
• Creep
• Non-linearity
• Repeatability rating

These must fall within the measuring system’s requirements. All load cells require periodic calibration and maintenance to stay within these error specifications with repeated use.

The quality of your load cell will affect not only its durability and performance but how easily it maintains calibration.

Choose a double-ended shear beam load cell that meets your accuracy requirements and has both quality construction and ergonomic design.

5. Select the Load Cell Type for the Application

Now you completely understand the main forces creating stress on an object and the other factors determining the selection of a load cell, we can discuss bending and shear force load cells to their optimal application.

Bending and Shear Force Load Cells:

Loads that feature bending movements or cause shear stresses require a specialized load cell to be measured.

That’s where the shear beam load cell comes for the rescue and by aligning vertically to the load, it records the weighing measurements.

However, a shear beam load cell cannot compensate well for torsion or other significant side loads out of place with the loading path.

1. Double-ended shear beam: It functions similarly to single-ended. However, a double-ended shear beam load cell is fixed at both ends and the load is applied to the midway point.

It has higher load capacity ratings than any other, so when supporting greater loads with size constraints, implement double-ended load cells.

The primary use of this load cell is in industrial weighing applications such as floor scales, weighing tanks, and other vessels.

Features & Applications of Double-Ended Shear Beam Load Cell

Manufacturers like CUBLiFT ergonomically design and manufacture double-ended shear beam load cells in a controlled environment to achieve ultimate performance and accuracy.

These load cells later become an excellent option for many industrial applications. They are available in alloy, stainless steel, aluminum, and tool steel.

Double-ended shear beam load cells are popular in the floor scales, conveyor weighing, and heavy-duty weighing of trucks, vessels, and tanks.

These beams have fixed ends on both ends. with the load point at the center of the load cell.

These high-capacity load sells can even handle 100 tons of load and are environmentally sealed with IP68 protection class.

Double-ended shear beam load cells are environmentally sealed for absolute water protection, providing protection against corrosive, caustic, and wet environments.

Every standard double-ended shear beam load cell contains the following features:

• IP68 protection class
• Environmentally-sealed
• Precision engineering
• Stainless steel, aluminum, alloy, or tool steel construction
• Maximum capacity of 100 tons
• Excellent on-board weighing applications
• Minimizes height increase
• Neutralizes side forces
• High capacity with minimal footprint
• Reduce material and labor costs
• High output – well suited to high dead-load/low live-load applications
• Load cells have matched outputs for multi-cell systems
• Excellent combined error and repeatability
• Integral conduit adaptor

Moreover, the applications of double-ended shear beam load cells involve the following:

• Tank, bin, and silo weighing
• Batching, blending, and mixing systems
• Level and inventory monitoring

Even in versatile industrial and weather conditions, they do not lose performance and accuracy.

It is versatile for use in both dynamic and static applications. The load cell design configuration ensures that its output is not affected by lateral loads.

Due to their ergonomic & low-profile design, the double-ended shear beam load cells improve mounting requirements by reducing the fabrication associated with the load cell and reducing equipment height.

Working Principle & Design of the Double-Ended Shear Beam Load Cell

It’s arguably the most common type of load cell in use for heavy weighing today.

Double-ended load cells work on the mechanism where when subjected to force, they slightly flex.

The double-ended design on the shear beam load cell is mounted at each end and loaded in the center, more akin to a hammock.

They cover an extensive range of possible capacities, accessories, and diverse mounting options.

Shear beam load cells represent the largest and most versatile group of load cells.

Working Principle:

A double-ended shear beam load cell, like any other modern load cell, is a transducer to convert force/weight into an electrical signal by way of strain gauges. The body of this load cell flex and react to the load/force applied.

Strain gauges are strategically positioned and secured to the surface of the load cell that also reacts to the applied load and record, calculate, and convert force into an electrical signal that holds the accurate weighing measurements.

Design:

In order to accommodate a vast library of applications and weighing processes, shear beam load cells come in different shapes and sizes.

In general, all of the double-ended shear beam load cells have a relatively low vertical profile relative to their length.

Shear beam load cells feature a machined recess in each side of the load cell, leaving a relatively thin vertical web in the center.

What gives the shear beam load cell its cross-sectional appearance is its thin vertical web.

The surface of this thin vertical web features strain gauges which are mounted at a 45-degree angle on each side to detect the strain.

At the same time, what helps it resist any movement or bending is its top and bottom flanges.

What makes double-ended shear beam load cells so popular among medium and high capacity applications is their excellent resistance to side forces.

These load cells are not for low capacity weighing as their web is not thin enough to obtain the necessary strain levels.

Technical Specifications of the Double-Ended Shear Beam Load Cell

The primary use of double-ended shear beam load cells is for industrial applications, as they’re designed and manufactured to withstand adverse operating conditions.

This load cell is resistant against dust ingress, splash water, extreme temperatures, and even immersion.

The design of a double-ended shear beam load cell gives excellent performance for high-capacity loading.

The following are the technical specifications of a standard double-ended shear beam load cell:

• Minimum load cell verification interval: Vmin = EMax / 10.000
• 6-wire shielded cable, 15m long
• Combined error 0,03% of Full-Scale Output (F.S.)
• Ultimate Overload: 300% F.S.
• Full Scale Output: 2mV/V +/- 0,1%
• Safe Overload: 150% F.S.
• Temperature effect on zero: 0,00116% /°C
• Insulation Resistance: >5000 MOhm
• Temperature effect on full scale output: 0,00097% /°C
• Zero Balance: +/- 1% F.S.
• Compensated Temperature Range: -10°C/+40°C
• Operating Temperature Range: -30°C/+85°C
• Input Resistance: 700 ± 7 Ohm
• Output Resistance: 700 ± 7 Ohm
• Creep error after 30 minutes: <0,02% F.S.
• Maximum tolerated excitation voltage: 15 VDC

These specifications are subject to change with each double-ended shear beam load cell design.

These high capacities and high-resolution load cells feature shielded connection cable, >C4 precision class, and >IP68 protection.

Furthermore, they provide good resistance to possible movement of the tanks and eliminate the need for check rods.

The Importance of Double-Ended Shear Beam Load Cell in Our Industry

These incredibly diverse shear beam load cells are capable of replacing the load cells in every medium and heavy-load weighing equipment due to their ergonomic design, ultimate precision, and great resistance against versatile conditions and environments.

The double-ended shear beam load cell is by far the most popular and exclusive load cell for floor scales due to its high capacity options and low height requirements.

CUBLiFT’s double-ended shear beam load cells are one of the best in the market because of their highest specifications for process weighing and industrial-scale applications.

Our fully welded and hermetically sealed shear beam load cells provide total environmental protection for use in harsh industrial environments.

Double-ended shear beam load cells have excellent accuracy and offer long-term stability for use in high-temperature metal industry applications with up to 150°C continuous operations.

It’s primarily manufactured in stainless steel and is hermetically sealed to IP68. It’s especially suitable for weighing vessels that are agitated or subject to major thermal forces.