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D4403-20 – Standard Test Method Technical Guide
📜 Scope and Application
This practice covers the description, application, selection, installation, data collecting, and data reduction of contact type extensometers used in rock mechanics. It is limited to contact-type devices; laser or non-contact extensometers are excluded. The values stated in inch-pound units are standard, with SI units provided for reference. All observed and calculated values must conform to Practice D6026 for significant digits and rounding. This practice offers instructions for specific operations and should be used with professional judgment, as it does not replace education or experience. Not all aspects are applicable in every circumstance.
⚙️ Instrumentation and Limitations
The standard outlines limitations for each extensometer system in Section 5. These limitations are crucial for proper selection and application. Users must consider project-specific constraints. The use of inch-pound units is standard, and reporting in other units is not considered nonconformance. This practice does not address all safety concerns; users are responsible for establishing safety and health practices.
⚠️ Warning: This standard does not address all safety concerns; users must establish appropriate safety practices and determine regulatory compliance.
📊 Data Handling and Significance
Extensometers are widely used in engineering to measure displacements. This practice provides industry-standard procedures for data collection and reduction. Data must be recorded and calculated following the guidelines in this standard and referenced documents like D6026. It is beyond the scope to consider significant digits for analysis methods in engineering design. Professionals should use these practices with experience and judgment.
| 🔍 Standard Number | 📄 Title |
|---|---|
| D653 | Terminology Relating to Soil, Rock, and Contained Fluids |
| D3740 | Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction |
| D6026 | Practice for Using Significant Digits in Geotechnical Data |
💡 Tip: Always verify the limitations of your specific extensometer system as outlined in Section 5 of the standard to ensure accurate measurements.
❓ Frequently Asked Questions
🔍 What types of extensometers are covered by this standard? Only contact-type extensometers are covered; laser or non-contact devices are not included.
💡 What units are used in the standard? Inch-pound units are standard, with SI units provided for information.
⚡ How should significant digits be handled? Follow Practice D6026 for significant digits and rounding in geotechnical data.
📌 Is this standard a substitute for professional judgment? No, it is intended for use with professional judgment and does not replace education or experience.