Digital Load Cell vs. Analog Load Cell

Load cells are responsible for measuring the weight or force applied on a scale. In essence, load cells determine the accuracy of a weighing balance. There are two primary forms of load cells, analog and digital. In this article, we're gonna make a simple differentiation of both.

Simply put, the difference between an analog and a digital load cell sensor is how their signal is processed. They differ in three major ways: signal strength, signal content and data sample rate.

• Signal Strength. Strain gauge signals begin with analog electrical voltages in both analog and digital cells, but with digital cells, the voltage readings are automatically converted into digital signals using an A/D processor. The analog cell has a very low magnitude of 0.03V signal while a digital cell's communication voltage signals commonly use 2 to 6 volts as their signal range, which is less sensitive to fluctuation. The result is a stronger and more accurate signal reading from the digital load cell compared to the analog cell.
• Signal Content. Analog load cells process the electrical voltage signals, which are then converted and displayed as weight readings in the indicator. In contrast, digital load cells transmit data from each load cell in a binary language like computers use. The binary data is not susceptible to interference from radio frequencies, electromagnetism, extreme temperatures and other factors that may hinder the accuracy of the weighing process. This simply means that digital cells offer a more reliable weight reading than analog cells. Additionally, more information from the load cell can be communicated, not just the weight reading. As such, the signal content is improved.
• Data Sample Rate. Data sample rate is basically the "time" it takes for the load cell to send a signal out for the weighing information to be read, processed, displayed. Analog load cells provide weight information continuously in real-time, whereas the sampling rate in a digital system is very fast as digital cells send weight information in bits, many times per second.

So what's better, analog or digital load cells? Both have pros and cons. Analog load cells are ideal for low duty-cycle and low commodity value applications. Also, they are low cost and easily sourced. However, longevity and durability are equally important factors to be taken into account. Digital load cells, while expensive, are less likely to break down and promise longer serviceability, and they provide more advanced capabilities. ATO store provides a wide variety of load cells and other products related to the load cell sensor. Also, if you want to know more about load cell, please click this video.