A load cell or loadcell is a highly accurate device that is used to measure weight or force in a number of different applications. They can be used to measure compression, tension, bending or shear forces.
The load cell itself is a transducer that is used to convert force into an electrical signal. Within the load cell structure is an area, or group of areas, which are designed to be stressed when a load/force is applied, normally in a linear fashion. Strain gauges manufactured from metal foil are bonded to these areas to sense the strain in the load cell structure under the applied load or pressure, and then provide a electrical output signal proportional to the strain when excited by a regulated voltage or current source. This signal is usually only a few millivolts and usually requires amplificationbefore it can be read.
Most load cells utilise strain gauge technology as it is very well established hand has been a proven technology for more than 40 years.
There seems to be so many types - I'm confused!
There are indeed many different types of load cells available from different manufacturers. This is necessary to meet the demands of the many applications that there are for load cells.
Luckily manufacturers and industry have kept nomenclature easy and the names of the load cells do correspond to the forces they measure. However, there are different types of load cell within each category, usually based on their manufacture and we have given you examples of these in the overview of each type of load cell. Alternative names are often based on the ‘shape’ of the load cell eg. S-beam, beam load cell and column load cell.
Load measuring pins are designed for many diverse applications as direct replacements for clevis or pivot pins. They have many advantages over other load sensors in that they do not normally require any change to the mechanical structure being monitored. They are typically used in rope, chain and brake anchors, sheaves, shackles, bearing blocks and pivots. You can find more information on LCM Systems’ Technical Note.
Products that fall under this category are also known as; load pin, shackle load pin and cevis pin. An example of aload measuring pin can be seen in image 2.
There are many situations where the use of traditional cabled load cells would limit distance or movement, or where, for safety reasons, a greater distance is needed between the user and the load. They are far more convenient to use, as they remove problems associated with long lengths of trailing cable that are easily damaged and prone to snagging. And it's not just the logistics of the applications that add to the advantages of radio telemetry. Considerable savings can also be made, as there are no cable costs or expenses for associatied wiring installation, that may in turn involve additional building modifications or maintenance issues.
LCM Systems offer many telemetry options that can improve load cell applications.
What do I do with the Load Cell signal to make it useful to me???
We know that a load cell is a transducer that is used to convert a force into an electrical signal. However, the electrical signal is very small and therefore, in many cases, will need amplifying before it can be used. As the name suggests, load cell amplifiers are used to magnify low level input signals from load cells into a stable industry standard process signal. Depending on the application, different types of amplifiers or conditioners are available. These include simple internal amplifiers, wireless telemetry systems, strain gauge digitisers and USB conditioning modules.
Also, few load cells actually have a display, so it is important to add an indicator to your system so you know the output. Indicators can be either wired or wireless, fixed or handheld.
LCM Systems can help you choose the correct load cell for your application. This is our expertise! Don't try to wade through many manufacturers data, when you can make a single call to LCM Systems.
To download a copy of this technical information sheet, please click here
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