Transducers – Load cells: A load cell is primarily used to measure which mechanical quantity in process/industrial applications?

Introduction / Context:
Load cells are fundamental transducers in weighing systems, batching, and force measurement. Understanding what they directly measure clarifies sensor selection.

Given Data / Assumptions:

• Common types: strain-gauge load cells, hydraulic/pneumatic load cells.
• Output is proportional to applied force due to weight or load.

Concept / Approach:
A load cell converts force (often the weight of an object under gravity) into an electrical or pressure signal. Strain gauges bonded to an elastic element sense minute deformation; the electronics report the applied force, calibrated in newtons or kilograms-force.

Step-by-Step Solution:
Define measurand → force.Relate to application → scales and hoppers measure weight via load cells.Hence the correct answer is weight (force).

Verification / Alternative check:
Manufacturer datasheets specify rated capacity in kN, lbf, or kgf, reinforcing that the primary measurand is force.

Why Other Options Are Wrong:

• Stress/strain are internal quantities; a strain gauge senses strain, but the calibrated output of a load cell is force (weight).
• Velocity/displacement are not the direct measurands of load cells.

Common Pitfalls:
Confusing the internal sensing principle (strain) with the external measurand (force/weight).

Final Answer:
Weight (force)