Accredited S-Type Load Cell Calibration Services
S-Type load cells (also known as S-Beam load cells) are the workhorses of the weighing and force measurement industry, valued for their versatility in both hanging tension and inline compression applications. At DRS Technologies, we provide expert calibration services to ensure your S-Type sensors deliver linear, repeatable, and accurate data. Our laboratory utilizes precision dead weight and hydraulic Force Testing transfer standards to verify your cells across their entire rated capacity.
Why Bidirectional Accuracy is Critical
Because S-Type load cells are often used in systems that switch between tension and compression—such as tank weighing, hoists, or material testing—they must be calibrated in both directions. Over time, mechanical fatigue or “off-center” loading can cause the internal spring element to lose its linearity. Regular calibration by DRS Technologies ensures that your “zero-balance” is stable and that your output ($mV/V$) remains precise, preventing errors in inventory or structural safety.
Our Technical S-Type Calibration Process
Our metrology specialists follow a rigorous multi-step protocol to ensure your sensor meets manufacturer specifications:
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Mechanical and Thread Inspection: We inspect the threaded mounting holes for wear or deformation. Damaged threads can lead to “side-loading” errors that skew force measurement.
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Zero-Balance and Bridge Resistance Audit: We measure the “no-load” output signal and the input/output resistance of the strain gauge bridge to identify potential electrical drift or moisture ingress.
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Linearity and Hysteresis Testing: We apply force in discrete increments (e.g., 0%, 20%, 40%, 60%, 80%, 100%) in both tension and compression. This verifies how the sensor responds as load is added and removed.
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Repeatability Verification: We perform multiple load cycles to ensure the sensor returns the same output for the same applied force, which is essential for consistent process control.
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Certification and NIST Traceability: Every service includes a detailed calibration certificate featuring “As-Found” and “As-Left” data, sensitivity measurements ($mV/V$), and documented NIST traceability.
Specialized Support for S-Beam Applications
DRS Technologies supports S-Type load cells across a wide range of industrial applications:
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Hanging Scales and Hoists: Verifying tension accuracy for safety-critical lifting.
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Tank and Hopper Weighing: Ensuring precise inventory measurement for bulk materials.
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Mechanical Test Stands: Calibrating sensors used in component pull-testing and assembly presses.
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Universal Testing Machine (UTM) Retrofits: Verifying S-Beam sensors used as primary force transducers in custom frames.
Frequently Asked Questions
Why is “Off-Center” loading a problem for S-Type load cells?
S-Type cells are designed to measure force through their central axis. If the load is applied at an angle or offset from the center, it introduces “bending moments” that the strain gauges will incorrectly interpret as vertical force. During calibration, we ensure your mounting hardware is properly aligned to eliminate these errors.
How often should an S-Type load cell be calibrated?
The industry standard is twelve months. However, if the load cell is subjected to “shock loads” (sudden impacts) or is used in outdoor environments with high humidity and temperature swings, a six-month interval is recommended.
Can you calibrate the load cell and the digital indicator together?
Yes. We highly recommend “system calibration,” where the load cell and the display unit are calibrated as a matched set. This accounts for any errors in the signal conditioning electronics and ensures the weight you see on the screen is exactly what the sensor is feeling.