What is a Load Cell?
A load cell is a transducer or a sensor, which converts the force or load into the electronic signal.
Depending on the type of the load cell and the circuit being used, the electronic signal can be of various kinds like Voltage change, current change or a frequency change.
The load cells are of various kinds and Strain gauge load cells are the most common type of load cells. The load cells are also classified based on a various basis.
Here are some types:
Depending upon the capacity of load cells, the types of load cells are as follows:
Low Capacity Load Cells
Ideal for the medical testing purpose or for wind tunnel testing and other such purposes, the low capacity load cells comes in use. These range from 25 grams to 150 pounds capacity and are classified under low capacity load cells.
Mid-Range Load Cells
The mid ranged load cells are designed with a capacity of 200 at a minimum to a maximum of 20000 pounds and are a perfect fit for the accurate weight measurements. These are widely used for the industrial purposes and measurement of equipment bolt force etc.
High Capacity Load Cells
High capacity load cells have the capacity ranging from the 25000 to 1 million pounds and come in use for several destructive and nondestructive testing purposes in labs and other places like concrete batch plants and mills, etc.
They are also perfect for several submersible and underwater measurements and are designed to carry such measurements, too.
Resistive load cells
Resistive load cells work on the principle of piezoresistivity. The working principle of Resistive load cells is “When a load, force or stress is applied to the sensor, there is a change in resistance.
This change in resistance results to a change in output voltage when an input voltage is applied.”
Capacitive Load Cells
Capacitive load cells work on the principle of capacitance. The capacitance is the ability of a system to hold a certain amount of charge when a voltage is applied to it. The working principle of these capacitive load cells is “For common parallel plate capacitors, the capacitance is directly proportional to the amount of overlap of the plates and the dielectric between the plates and inversely proportional to the gap between the plates.”
Hydraulic Load cells
Hydraulic load cells are the force balanced cells, which are used to measure weight, which gets generated by a change in the pressure of the internal filled in a fluid.
The working principle of hydraulic load cells is “When a load or force acts on a loading head, it is transferred to a piston that in turn compresses a filling fluid confined within an elastomeric diaphragm chamber. With the increase in force, the pressure of the hydraulic fluid increases. This pressure can be locally indicated or transmitted for remote indication or control”.
Pneumatic load cells
Pneumatic load cells are the ones, which operates on the force-balance principle. The Pneumatic load cells are known to provide higher accuracy in comparison to a hydraulic device since they use multiple dampener chambers.
These Pneumatic load cells are often used to measure relatively small weights in places like industries where cleanliness and safety are the highest priority.
The load cells are of various kinds. It is you, who must decide, what kind of load cells are to be used. The selection of a load cell can be based on the following criteria:
● Type of load cells
● Size of load cells
● Accuracy of load cells
● Weight range of load cells
● Mounting criteria of load cells
● Operating temperature of load cells
● Duration of measurements of load cells
● Output type
● Cost of the chosen load cells
● Direction of loading
Load cells are used for the accurate and precise measurements and the measurement time out is also very quick. In comparison to the other sensors, these load cells are very affordable and also bears longer life span.
We recommend using load cells for the various advantages associated and since they come cheap, they are perfect for your measurement needs.