UNLIMITED FREE ACCESS TO THE WORLD'S BEST IDEAS

close
Already an Engineering360 user? Log in.

This is embarrasing...

An error occurred while processing the form. Please try again in a few minutes.

Customize Your Engineering360 Experience

close
Privacy Policy

This is embarrasing...

An error occurred while processing the form. Please try again in a few minutes.

Webinars & White Papers

ASTM E251

Standard Test Methods for Performance Characteristics of Metallic Bonded Resistance Strain Gauges

inactive
Buy Now
Organization: ASTM
Publication Date: 15 January 1992
Status: inactive
Page Count: 20
ICS Code (Mechanical testing): 19.060
scope:

The purpose of this standard is to provide uniform test methods for the determination of strain gauge performance characteristics. Suggested testing equipment designs are included.

Strain gauges are very sensitive devices with essentially infinite resolution. Their response to strain, however, is low and great care must be exercised in their use. The performance characteristics identified by these test methods must be known to an acceptable accuracy to obtain meaningful results in field applications.

Strain gauge resistance is used to balance instrumentation circuits and to provide a reference value for measurements since all data are related to a change in the gauge resistance from a known reference value.

Gauge factor is the transfer function of a strain gauge. It relates resistance change in the gauge and strain to which it is subjected. Accuracy of strain gauge data can be no better than the precision of the gauge factor.

Changes in gauge factor as temperature varies also affect accuracy although to a much lesser degree since variations are usually small.

Transverse sensitivity is a measure of the strain gauge's response to strains perpendicular to its measurement axis. Although transverse sensitivity is usually much less than 10 % of the gauge factor, large errors can occur if the value is not known with reasonable precision.

Thermal output is the response of a strain gauge to temperature changes. Thermal output is an additive (not multiplicative) error. Therefore, it can often be much larger than the gauge output from structural loading. To correct for these effects, thermal output must be determined from gauges bonded to specimens of the same material on which the tests are to run; often to the test structure itself.

Bonded resistance strain gauges differ from extensometers in that they measure average unit elongation (DL/L) over a nominal gauge length rather than total elongation between definite gauge points. Practice E 83 is not applicable to these gauges.

These test methods do not apply to transducers, such as load cells and extensometers, that use bonded resistance strain gauges as sensing elements.

Strain gauges are part of a complex system that includes structure, adhesive, gauge, leadwires, instrumentation, and (often) environmental protection. As a result, many things affect the performance of strain gauges, including user technique. A further complication is that strain gauges once installed normally cannot be reinstalled in another location. Therefore, gauge characteristics can be stated only on a statistical basis.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Document History

June 1, 2020
Standard Test Methods for Performance Characteristics of Metallic Bonded Resistance Strain Gages
The purpose of these test methods are to provide uniform test methods for the determination of strain gage performance characteristics. Suggested testing equipment designs are included. Strain gages...
May 1, 2020
Standard Test Methods for Performance Characteristics of Metallic Bonded Resistance Strain Gages
The purpose of these test methods are to provide uniform test methods for the determination of strain gage performance characteristics. Suggested testing equipment designs are included. Strain gages...
ASTM E251
January 15, 1992
Standard Test Methods for Performance Characteristics of Metallic Bonded Resistance Strain Gauges
The purpose of this standard is to provide uniform test methods for the determination of strain gauge performance characteristics. Suggested testing equipment designs are included. Strain gauges are...
January 15, 1992
Standard Test Methods for Performance Characteristics of Metallic Bonded Resistance Strain Gages
The purpose of these test methods are to provide uniform test methods for the determination of strain gage performance characteristics. Suggested testing equipment designs are included.  Test...
January 15, 1992
Standard Test Methods for Performance Characteristics of Metallic Bonded Resistance Strain Gages
1. Scope 1.1 The purpose of this standard is to provide uniform test methods for the determination of strain gage performance characteristics. Suggested testing equipment designs are included. 1.2...
January 15, 1992
Standard Test Methods for Performance Characteristics of Metallic Bonded Resistance Strain Gages
The purpose of this standard is to provide uniform test methods for the determination of strain gage performance characteristics. Suggested testing equipment designs are included. Test Methods E 251...
February 28, 1986
STANDARD TEST METHODS FOR PERFORMANCE CHARACTERISTICS OF BONDED RESISTANCE STRAIN GAGES
A description is not available for this item.
September 8, 1967
STANDARD TEST METHODS FOR PERFORMANCE CHARACTERISTICS OF BONDED RESISTANCE STRAIN GAGES (R 1980) (E1-1985)
A description is not available for this item.

References

Advertisement