Question

Among bonded metal strain gauges, the foil type is more popular than wire type because:

• A. Error due to transverse strain is much less in foil type
• B. Gauge factor is much high in foil type
• C. Foil type is more insensitive to temperature variations
• D. Error due to transverse strain is much high in foil type

Hint:

Foil strain gauges offer better accuracy and lower sensitivity to unwanted strain directions.

Answer 1

The Correct Option is A

In instrumentation engineering, strain gauges are devices used to measure the amount of deformation or strain in an object. There are two common types of bonded metal strain gauges: foil type and wire type. Understanding the advantages of foil type gauges helps in selecting the right gauge for specific applications.

The correct answer to why foil-type gauges are more popular is that error due to transverse strain is much less in foil type.

Here's why:

• Transverse Strain Sensitivity: Transverse strain refers to the strain occurring perpendicular to the direction of the gauge's primary measurement axis. In foil-type gauges, the configuration and design make them less sensitive to these transverse strains compared to wire-type gauges. This reduced sensitivity leads to more accurate measurements.
• Design Considerations: The foil-type gauge consists of a thin metal foil which can be arranged in a grid pattern, allowing for even distribution of stress. This design inherently minimizes the potential for errors due to transverse strains, compared to the spiral or helical pattern typically used in wire-type gauges.

While other factors such as gauge factor and temperature sensitivity can influence gauge selection, the primary reason why foil-types are favored over wire-types is their reduced error due to transverse strain, making them the more reliable and preferred choice in many engineering applications.