Load Cell, Weigh Module, Load Sensor

What is a load cell?
A scale load cell, or load sensor, is used in variety of industries in which precise measurements are needed. Without accurate measurements, companies can lose money or give away product. Digital load cells offer unparalleled accuracy compared to analog load cells. Load cells accurately measure the weight of tanks, vessels, hoppers or conveyors. Our load cell technology is built to withstand the demands of a variety of rugged industrial applications. The capacity of load cells can greatly vary. Some load cells are more appropriate for laboratory applications, while others are more appropriate for high-capacity batches or logistics applications.

METTLER TOLEDO’s robust high-precision load cells meet all globally-required approvals and standards. They include single-ended beam load cells that allow you to change your structure into a scale. Beam load cells are used in multiples in floor scales, belt weighers, weighing systems, pallet scales, checkweigher scales and conveyor scales. Most METTLER TOLEDO load cells can be globally used in legal weighing systems, and are mostly made from stainless steel to cope with harsh industrial environments. Canister/ring load-cell technology features robustness for harsh environments as well. These are typically used in tank scales, vessel weighing, silo scales and truck weighing.

How does a load cell work?
Load cells work by converting a weight reading into a signal that is then read by a computer located somewhere else, called the terminal. Load cell technology is easily integrated into many kinds of instruments, machines, vehicles and other devices.

Load cell systems are essential to accurate weight readings. Without precise and highly durable load cells, you cannot weigh with confidence. Durable, well-designed load cells, sensors and weigh modules from METTLER TOLEDO can withstand heavy-duty loads while remaining highly accurate and reliable. Our weigh modules have incorporated overload and lift-off protection to preserve fast weighing and accurate results for a long lifetime. They withstand vibrations, aggressive raw materials, wind forces, temperature fluctuations and torques from mixers.

What are load cells used for?
Load cells are used to measure the weight of any possible material. They reach from microgram to several hundred (100) tons. Low weights are required for pharma applications where fractions of a gram can make a key difference. Mid-size load cells are typically used for processing and trading materials. Large capacities are used for storage applications.

How accurate are load cells?
Very often accuracy and resolution are mixed. Resolution is how many digits are displayed, but more digits does not mean better accuracy. Accuracy describes how true the weighing results are. For good reason, legal-for-trade scales limit resolution to eliminate getting into the interpretation of results. Therefore, the best benchmarks for accuracy are legal-for-trade approvals. Strain-gauge load cells typically provide accuracy from 1/3,000d to 1/10,000d. Load cells using force restoration reach 1/200,000 or even better. Under ideal conditions, which include constant temperature and humidity, the accuracy can be 5-10 times better.

What is load cell calibration?
Calibration is a process that assesses the accuracy of a load cell to ensure weighing results remain within predefined tolerances. Load cells need to be calibrated  where they will be used. The primary reason for onsite calibration is that gravity changes by location. A load cell manufactured in location A and used in location B would create an error without onsite calibration. Another reason onsite calibration is important is the ongoing wear on the device itself to which all technical instruments are subject. Depending on the importance of accuracy in the process in which the scale is used, it is good practice to calibrate a scale every 1-2 years. 

What is the output of load cell?
Most load cells provide an analog output of 2-3 mV/V. Since these are passive devices, they need an external power source for excitation. The output signal varies related to the relative excitation voltage and current load. Thus, it is crucial to have a very stable excitation source that eliminates effects cause by the power source. A 2mV/V load cell provides as little as 20mV output at full capacity when powered with 10V output. Modern terminals provide both a stable power source and accurate amplification of the output signal to convert results into digital information.  

How many types of load cell are there?
Load cells are first distinguished by their form. Single-point load cells are used for small and mid-size applications. Beam load cells are used for floor scales and mid-size tank scales. Canister load cells are used for heavy-capacity applications. Another separation criteria for load-cell type is the output provided. Analog load cells need an external terminal for amplification and A/D conversion while POWERCELL load cells have in-built "intelligence" with the advantage of better accuracy, much more robust data transfer and the potential to monitor the condition of the load cell to help with maintenance.

What is function of load cell?
A load cell is a force-measuring device. Load cells do not measure mass directly, they measure the gravitational force created by the Earth’s mass on another weighed mass. This is the reason a load cell needs to be calibrated onsite, as gravity changes by location.

What is the difference between load cell and strain gauge?
Strain gauges are components of load cells. Load cells are a counterforce that converts load into strain. That strain is taken by the strain gauge which changes its resistance into an electrical quantity that can be measured and reported as a weighing result. 

What is excitation voltage for a load cell?
Load cells are passive devices that need an external power source for excitation. Related to that excitation, voltage can change based on the current load, causing errors. Therefore, it is crucial to have a very stable excitation source to eliminate errors caused by the power source. Modern terminals provide a stable power source, accurate amplification of the small output signal, and conversion of results into digital information.

What is hydraulic load cell?
Hydraulic load cells use the principle of pressure change when loading an enclosed fluid. The pressure change is measured by a pressure transducer. Hydraulic load cells are not very accurate and not very common these days. The advantage of robustness that they offered in times when electronics were not as accurate are long gone.

Are load cells linear?
Typically load cells are very linear to 0.03% or even much better. Scales today are primarily only calibrated at zero and a maximum span point indicating that the range in-between is linear.

How do you calculate load cell capacity?
Load cells measure both the dead load and the net load of a scale, so this needs to be considered when calculating load cell capacity. How the goods are positioned on the scale also matters. Using load cells that are larger than they need to be for a given application is not recommended as accuracy suffers. For scales where the goods are mostly centered — which is true for most tank, silo and vessel scales — the formula is:
C >= sf*(TDL+SC)/N        (eg. tank scales)

For scales with four load cells where the goods are likely to be positioned off-center — which is true for floor, small truck and conveyor scales — the formula is:
C >= sf*(TDL/4 + SC/2)   (eg. floor, small vehicle scales, conveyors)

C = LC or Weigh module capacity
TDL = Total dead load
SC = Scale capacity
sf = Safety factor (typically 1.25)
N = Number of load cells or weigh modules

Seek professional consulting for more complicated systems.

How can I buy load cells?
METTLER TOLEDO has load cells for sale in all regions. METTLER TOLEDO is your single source to look for load cell for sale. Our load cells are industry leading in accuracy and reliability

What is a load cell sensor?
A scale load cell, or load sensor, or dynamic load cell is used in variety of industries in which precise measurements are needed. Without accurate measurements, companies can lose money or give away product. Digital load cells offer unparalleled accuracy compared to analog load cells. Load cells accurately measure the weight of tanks, vessels, hoppers or conveyors. Our load cell technology is built to withstand the demands of a variety of rugged industrial applications. The capacity of load cells can greatly vary. Some load cells are more appropriate for laboratory applications, while others are more appropriate for high-capacity batches or logistics applications.

METTLER TOLEDO’s robust high-precision load cells meet all globally-required approvals and standards. They include single-ended beam load cells that allow you to change your structure into a scale. Beam load cells are used in multiples in floor scales, belt weighers, weighing systems, pallet scales, checkweighing scales and conveyor scales. Most METTLER TOLEDO load cells can be globally used in legal weighing systems, and are mostly made from stainless steel to cope with harsh industrial environments. Canister/ring load-cell technology features robustness for harsh environments as well. These are typically used in tank scales, vessel weighing, silo scales and truck weighing.

What are the most common load cell types and applications?
Load cells come in a variety of types, including: analog load cells, digital load cells, POWERCELL load cells, tensile load cell solutions, load cell 50 ton varieties and much more. Common applications include either use in a standard scale, or use turning a structure into a scale – a weigh module would be more commonly the term used. METTLER TOLEDO offers a variety of load cell technology solutions and load cells for sale.

What are some things to consider before selecting the best load cell manufacturers?
First, it is important to consider your load cell specifications, this is determined by a load cell accuracy calculation, desired readability, and desired reliability. Additionally, consider the load cell capacity calculation, to see what options fit your largest and smallest weight. Load cell wiring is a consideration for placement and safety.

Other considerations around the world include:

• Do I require a micro load cell?
• Do I require a load cell zero balance?
• Do I require a 50kg load cell?
• Do I require 6 dof load cell?
• Do I require a crane load cell?
• Do I need a load cell reader or weight indicator load cell solution?
• What load cell companies are in my region?

1. Load cell manufacturers in the USA
2. Load cell Philippines providers
    

• What load cell cable solutions do I require?
• How much do I want to pay for a load cell scale?

1. What load cell price am I willing to pay for requirements?
2. What is the difference in cost for digital load cell price solutions?
3. What is the digital load cell price in India?