An Introduction to Load Cell Amplifiers
AN INTRODUCTION TO LOAD CELL AMPLIFIERS
Industrial load cell amplifiers are useful devices that can be used alongside load cells in order to allow users to measure and monitor their data, as well as improving the accuracy. Read on to find out what a load cell amplifier is, how they work and whether or not you should be using one.
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What is a load cell amplifier?
A load cell is a sensor that converts force energy into a measurable electrical signal (think weighing scales and balances). A load cell amplifier is a device used to increase the signals generated by sensors to allow further processing and monitoring. Some load cells produce signals that are too weak, which can mean that they don’t work with certain components, such as PLC, displays, computers and data loggers.
Simply put, a load cell amplifier takes this low strength signal and amplifies it and converts it into a more useful signal that can be interpreted as necessary. Depending on the load cell amplifier, outputs can vary, although USB, RS-323, RS-485 and CC-Link are common.
For more information on load cells, see our blog post: Load Cells: A Beginners Guide.
How do load cell amplifiers work?
The original signal comes from the load cell, and is specifically produced by a strain gauge – a type of sensor whereby the electrical resistance changes when force is applied. Load cells usually produce signals in Mv (millivolt), which is not always useful when monitoring and interpreting your data. Such a weak signal can often be affected by ambient electrical noise, which can make measurements less accurate. This signal travels to the load cell amplifier, which uses DC power, and is converted into a standard analogue or digital output, commonly 4-20mA, 0-10V or +/- 10V.
This process of converting a signal is classed as signal conditioning, of which there are other types such as linearisation, excitation and filtering. The signal is now boosted to a point where it is able to displayed on a readout.
Using a load cell amplifier
Load cells are critical instruments for the measurement and monitoring of data, so it’s crucial that your load cell amplifier is correct for the application you want. Selecting the wrong load cell amplifier or using it incorrectly can alter load cell measurements and lead to inaccurate results. When using your amplifier, always make sure to follow the manufacturers instruction, which can usually be found in the user manual. It’s also important that operators have been properly trained to install and use the equipment.