There are two types of load cells: analog and digital. The most popular type is an analog cell that measures stress and weight strain. These strain gauge sensors are attached to the spring element of the load, and this will bend when weight is placed upon it. Digital differ from analog in how their signal is processed. There are three major differences:
- signal strength
- signal content
- data sampling rates
Analog Load Cells
Analog load cells are the most common type on the market. They are ideal for low duty-cycle and low commodity value applications. Also, they are low cost and easily sourced. There are many variations of load cells and mounts found in the marketplace. Typically Precision Scale uses shear beam, and compression canister analog load cells.
Digital Load Cells
A digital load cell has an advantage over an analog load cell due to signal strength. The analog cell has a very low magnitude (~ 0.3 V) signal while a digital cell’s communication voltage is usually between 2 – 6 Volts. This makes the signal less susceptible to interference, and is much stronger.
An analog system relies on the electrical voltage from one load cell to determine the weight reading. In contrast, digital systems transmit data from all of loads cell in binary format which is not susceptible to interference and less prone to weighing errors. Additionally, more information from the load cell can be communicated, not just the weight reading. As such, the signal content is improved.
The sampling rate in a digital system is very fast. Digital cells send weight information in bits, many times per second.