Circular Diaphragm Strain Gauge

The appropriate resistance value depends on the test equipment and application requirements. For general stress testing, 120Ω strain gauges are often used to match common instrumentation. For high-precision measurements such as pressure sensors, higher resistance strain gauges such as 350Ω, 500Ω, or 1000Ω are often selected to improve stability, sensitivity, and signal-to-noise ratio.

If the stress distribution on the specimen is uniform and the bonding area is large, a strain gauge with a grid length of 3–6 mm is recommended for ease of bonding and good heat dissipation. For areas of stress concentration or where space is limited, a small strain gauge with a grid length ≤ 1 mm is recommended, but the bonding quality and heat dissipation must be ensured.

The sensitive grid structure of the strain gauge depends on the nature of the stress being measured and whether the principal stress direction is known. If the principal stress direction is known, a uniaxial strain gauge can be used. If the principal stress direction is unknown or shear strain needs to be measured, a multiaxial strain gauge can be used.