Here’s a clear, engineering-level explanation of load cell accuracy vs calibration accuracy, because they are related but not the same thing:
1. Load Cell Accuracy
This refers to the intrinsic performance of the load cell itself — how close its output can be to the true value when everything is perfect (ideal conditions, correct instrumentation, and proper calibration).
Load cell accuracy is typically determined by combining several error components:
Components of Load Cell Accuracy
• Non-linearity – Deviation of the output curve from a straight line.
• Hysteresis – Difference in output when loading vs unloading.
• Repeatability – How consistently the load cell reproduces the same reading under identical conditions.
• Creep – Output change under constant load over time.
• Temperature effects – Zero and span shifts caused by temperature changes.
What it represents
• The accuracy the manufacturer designed and built into the sensor.
• A fundamental limit — calibration cannot make the load cell better than this
2. Calibration Accuracy
This refers to how accurately the load cell system (cell + indicator) has been calibrated against a known standard.
Calibration accuracy depends on:
Factors affecting calibration accuracy
• Quality/accuracy class of the reference weights or test machine
• How many calibration points are used
• Technician skill and procedure
• Environmental conditions during calibration
• Indicator resolution and linearity
• Whether the full measurement chain is calibrated together
What calibration accuracy means
• How close your calibrated system is to the true load.
• It is the actual usable accuracy in your installation.
🔍 Key Difference Explained in One Sentence
“Load cell accuracy is the maximum theoretical performance of the sensor, while calibration accuracy is the actual accuracy achieved after calibrating the whole system in real conditions.“
📌 Example:
A load cell datasheet might state:
• Accuracy (combined error): ±0.03% of full scale
But after calibration, depending on instruments and conditions, the system may achieve:
• Calibration accuracy: ±0.05% of reading
The calibration accuracy can be better or worse than the inherent load cell accuracy—
but the final system accuracy cannot exceed the load cell’s inherent capability.