Bending Beam Load Cell Basics
Bending beam load cells are versatile and cost-effective solutions for many weighing and force measurement applications. These miniature load cells are small in dimension, making them ideal for compact testing environments and for embedding into machines or products for continuous performance measurement.
Bending beam load cells are used across industries and applications, including weighing scales, medical devices, industrial process controls, robotic designs, packaging machinery, and civil engineering projects.
How Bending Beam Load Cells Work
A bending beam load cell converts a force applied to it into an electrical signal by measuring the flexure of the beam. This is done by attaching strain gages to the beam. When the beam bends, the strain gages change their resistance, which a Wheatstone bridge circuit converts into an electrical signal. The output signal is proportional to the applied load.
The bending beam load cell is bolted to a support through the two mounting holes. Under the covers, you can see the large hole bored through the beam. This forms thin sections at the top and bottom surfaces, which concentrate the forces into the area where Interface’s proprietary strain gages are mounted on the top and bottom faces of the beam. The gages may be mounted on the outside surface, as shown, or inside the large hole.
The compression load is applied at the end opposite the two mounting holes, usually to a load button that the user inserts into the loading hole.
MB Miniature Beam Load Cell
The Interface Model MB is a miniature beam load cell used in test machines and various low-capacity applications.
- Standard Capacities are 5 to 250 lbf (22.2 N to 1.11 kN)
- Proprietary Interface temperature-compensated strain gages
- Performance to 0.03%
- Low height – 0.99 in (25.1 mm)
- Eccentric load compensated
- ±0.0008% /˚F – max temperature effect on output
- Low deflection
MBI Overload Protected Miniature Beam Load Cell
Interface’s Model MBI Overload Protected Miniature Beam Load Cell has better resistance to off-axis loads then other similar load cells and is fatigue rated.
- Standard capacities from 2 to 10 lbf (10 to 50 N)
- Proprietary Interface temperature-compensated strain gages
- Performance to 0.03%
- Low height – 1in max
- ±0.0008% /˚F – max temperature effect on output
- 10x overload protection
MBP Overload Protected Miniature Beam Load Cell
Our Model MBP series Mini load cells provide similar performance to the Model MB series with the added safeguard of internal overload protection. This patented overload protection is achieved through hard stops EDM-machined into the load cell flexure. This provides greater overload protection (2.5-10lbf ±1000% of full-scale capacity, 100 N ±500% of full-scale capacity), giving the user added protection in more severe applications.
- Standard capacities from 2 to 10 lbf (10 to 50 N)
- Proprietary Interface temperature-compensated strain gages
- 10x overload protection
- Low height – 0.99 in (25.1 mm)
- ±0.0008% /˚F temp. effect on output
- 5′ Integral Cable (custom lengths available upon request)
- NIST Traceable Calibration Certificate
MBS Parallelogram Load Cell
The Interface MBS Parallelogram load cell is made of lightweight aluminum and is well-suited for medical and robotics applications.
- Capacities from 2.2 to 10 lbf (9.8 to 44.5 N)
- Lightweight
- Nonlinearity error 0.02% FS
- Ideal for OEM applications
Double Bending Beam Cells
Forming two bending beams into a single cell is a very useful variation of the bending beam design. This allows the loading fixtures to be attached to the threaded holes on the centerline between the beams, so the sensitive axis passes through the cell on a single line of action.
Bending Beam Load Cell Applications
Material testing is a common application for bending beam load cells. This type of miniature load cell measures forces applied to materials with high accuracy to determine the specimen’s stiffness, strength, and durability.
It is quite common to find bending beam load cells in industrial automation machines and robots to precisely measure the forces required for control, safety, and efficiency. In robotics, bending beam load cells measure the force applied to the robot’s arms and grippers. The data is used to control the robot’s movements and ensure that it does not damage the objects it is handling.
Aerospace engineering has long used bending beam load cells in the design, testing, and manufacturing of aircraft and spacecraft. Automotive engineering uses bending beam load cells to design and test vehicles for safety and reliability.
Interface’s ability to custom-design bending beam solutions that meet strict size, capacity, and accuracy requirements has made our products commonly used in medical and healthcare applications.
Bending Beam Application for Medical Device Testing
In this application, the medical device product lab must apply known forces to stents and catheters to ensure they pass all necessary strength and flexibility tests. MBP Overload Protected Beam Miniature Load Cell is placed behind the guide wire for the stent or catheter. The motor will spin the linear drive, push the load cell, and guide the wire through the testing maze. The bending beam load cell connects to the DIG-USB PC Interface Module to record and store testing data for analysis. Read more.
Bending Beam Application for Vertical Farming
Vertical farming is the production of crops in a vertical manner, using smart technology systems, indoors, with an irrigation system. A wireless force measurement solution is needed to monitor the amount of water used, ensuring the produce is watered just the right amount. Interface suggests installing four MBI Overload-Protected Miniature Beam Load Cells at each corner of the produce trays to accurately measure weight during watering. A JB104SS 4-Channel Stainless Steel Junction Box connects to each bending beam cell and to a WTS-AM-1E acquisition module. The device wirelessly transmits the sum weight to the WTS-BS-1-HA Wireless Handheld Display for multiple transmitters and the WTS-BS-6 Wireless Telemetry Dongle Base Station. Interface’s Wireless Telemetry System monitored and weighed the amount of water used on the produce in this vertical farming system to increase yield and conservation. Read more here.
Additional Resources
The Basics Of Shear And Bending Beams
Interface Mini™ Load Cell Selection Guide
