4 Wire Load Cell Wiring Diagram

When it comes to measuring weight or force, load cells are an essential component. A load cell is a type of transducer that converts force into an electrical signal. It is used in various applications such as laboratory testing, industrial automation, and medical equipment. One of the most common types of load cells is the 4 wire load cell. In this article, we will discuss the wiring diagram of a 4 wire load cell.

What Is a 4 Wire Load Cell?

A 4 wire load cell has four wires that are used for signal processing. These wires are connected to a Wheatstone bridge circuit that measures the resistance changes due to force or weight. Of these four wires, two are used for power supply, and the other two are used for signal output. By using a 4 wire load cell, we can achieve higher accuracy and stability in weight measurement.

How Does a 4 Wire Load Cell Work?

A 4 wire load cell works by measuring the change in resistance when a force is applied. When a force is applied to the load cell, it undergoes deformation, which causes the resistance of the strain gauge to change. This change in resistance is proportional to the applied force. The Wheatstone bridge circuit converts this change in resistance into a voltage signal, which is then amplified and processed by signal conditioning circuits.

The signal output from the 4 wire load cell is a differential output. This means that the voltage output is the difference between the two signal wires. By subtracting the voltage output of the two signal wires, we can eliminate any noise or interference in the signal.

4 Wire Load Cell Wiring Diagram

The wiring diagram of a 4 wire load cell is relatively simple. It consists of four wires: red, black, white, and green. The red and black wires are used for power supply, while the white and green wires are used for signal output.

Here is the wiring diagram of a 4 wire load cell:

Wire Color Description Connection
Red Power Supply (+) Excitation +
Black Power Supply (-) Excitation –
White Signal Output (+) Signal +
Green Signal Output (-) Signal –

It is essential to note that the power supply voltage should match the load cell’s rated voltage. For example, if the load cell is rated at 5V, then the excitation voltage should also be 5V.

How to Calibrate a 4 Wire Load Cell?

Calibrating a 4 wire load cell involves setting the output voltage of the load cell for a given force or weight. This is typically done using a calibration weight or a known force. Here are the steps to calibrate a 4 wire load cell:

  1. Apply a known weight or force to the load cell.
  2. Measure the voltage output of the load cell.
  3. Calculate the output voltage per unit of weight or force.
  4. Adjust the gain of the signal conditioning circuit to match the calculated value.

It is essential to perform regular calibrations to ensure that the load cell is functioning correctly and producing accurate results.

Conclusion

The wiring diagram of a 4 wire load cell is relatively simple, consisting of four wires for power supply and signal output. By using a 4 wire load cell, we can achieve higher accuracy and stability in weight measurement. To ensure accurate results, it is essential to calibrate the load cell regularly.

FAQs

What is the difference between a 4 wire and 6 wire load cell?

The main difference between a 4 wire and a 6 wire load cell is the number of wires used for signal output. A 4 wire load cell has two wires for signal output while a 6 wire load cell has four wires for signal output. This means that a 6 wire load cell can eliminate any lead wire resistance, resulting in higher accuracy and stability in weight measurement.

Can a load cell be connected directly to a microcontroller?

No, a load cell cannot be connected directly to a microcontroller. A load cell requires excitation voltage, and the output voltage needs to be amplified and processed by signal conditioning circuits before connecting it to a microcontroller.

What is the maximum capacity of a load cell?

The maximum capacity of a load cell varies depending on the application. Load cells range from a few grams to several tons in capacity.

What is a strain gauge?

A strain gauge is a type of sensor that is used to measure deformation or strain in an object. It is typically made of a thin metal foil that is attached to the surface of the object. When the object undergoes deformation or strain, the metal foil’s resistance changes, which is then converted into an electrical signal.