What is Load Cell Conditioning?
Load cells are essential tools for measuring force and weight in various applications, from industrial machinery to structures used for launching rockets. Interface Tech Talk answers the question, what is load cell conditioning, and why does it matter?
A load cell is a sensor that produces an output proportional to an applied load. Output is the algebraic difference between the signal at applied load and the signal at minimum load. The native mv/V from a load cell offers the most accurate force measurement.
Load cell conditioning takes the raw signal from a load cell and converts it into a form for further processing or display. The raw signal from a load cell is in the millivolt range. Load cell conditioning is valuable for amplifying, filtering, and converting the raw signal from a load cell.
Load Cell Conditioning Benefits
Load cell signal conditioners can improve the signal-to-noise ratio, convert the output into a preferred high-level signal type, and increase the electrical resolution for a given measurement.
- Amplification increases the signal strength to a level that can be more easily measured and processed.
- Filtering helps to remove this noise and improve the accuracy of the measurement. Load cells can be sensitive to noise, such as electrical interference or mechanical vibrations.
- Load cells require a stable excitation voltage. Load cell conditioners provide an excitation voltage output to ensure it operates within its specified range.
- The output signal from a load cell may have an offset or gain error. Load cell conditioners allow for the adjustment of these parameters to ensure the desired output signal.
- As analog moves to digital use cases, there is an increasing demand for conditioners to include an analog-to-digital converter (ADC) to convert the conditioned analog signal into a digital format. Learn more in Instrumentation Analog Versus Digital Outputs
TIP: It is important to understand if there is potential exposure to susceptible noise. Inline signal conditioning and signal conditioner instrumentation are preventative if noise or long cable runs are a concern in your test environment.
Choosing the Right Load Cell Signal Conditioner
When choosing a load cell conditioner, it is important to consider the specific requirements of your application.
- Type of Load Cell: Different types of load cells require different types of conditioning. Ensure that the load cell signal conditioner you choose is compatible with the type of load cell you use.
- Number of Channels: Using multiple load cells, you will need a load cell signal conditioner with multiple channels.
- Allowable Input Range: Ensure compatibility with the load cell’s full-scale output to avoid clipping the signal.
- Internal Filtering: If you use it with a dynamic application, ensure the filtering speed matches.
- Bandwidth of ADC: The converter must be strong enough to process the signal from analog to digital
- Output Signal: Choose a load cell signal conditioner with an output signal compatible with your data acquisition system or other equipment you pair with the transducer.
- Environmental Conditions: If the load cell conditioner will be used in a harsh environment, choose a model designed for those conditions.
Interface Signal Conditioners and Amplifiers
- DMA2 DIN Rail Mount Signal Conditioner
- ISG Isolated DIN Rail Mount Signal Conditioner
- SGA AC/DC Powered Signal Conditioner
- BSC1A Strain Gage Amplifier
- BSC4A Multi-Channel Analog Output Bridge Amplifier
- BSC6A-HD44 6-Channel Strain Gage Amplifier
- NEW! In-Line IO-Link Amplifier
Engineering Tip for Application of Calibration Loads: Conditioning the Cell
Any transducer that depends upon the deflection of a metal for its operation, such as a load cell, torque transducer, or pressure transducer, retains a history of its previous loadings. This effect occurs because the minute motions of the crystalline structure of the metal, small as they are, have a frictional component that shows up as hysteresis (non-repeating of measurements taken from different directions).
Before the calibration run, the history can be swept out of the load cell by applying three loadings, from zero to a load that exceeds the highest load in the calibration run. Usually, at least one load of 130% to 140% of the Rated Capacity is applied to allow the proper setting and jamming of the test fixtures into the load cell.
Please consult our Load Cell Field Guide for additional information on this topic. This must-have resource is available for download at no cost.
Load cell conditioning is critical in ensuring accurate and reliable weight and force measurements. By understanding the basics of load cell conditioning, you can choose the right equipment for your application and achieve the best possible results. If you have questions, please consult with our expert application engineers.
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