Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: AASHTO T 67:2008
• Năm ban hành / Publication date: 2008
• Tình trạng / Status: W - Hết hiệu lực
• Tên tiếng Anh / Title in English: Standard Method of Test for Standard Practices for Force Verification of Testing Machines
• Thay thế cho / Replace: AASHTO T 67:2005
• Số trang / Page: 11

Phạm vi áp dụng / Scope of standard

These practices cover procedures for the force verification, by
means of standard calibration devices, of tension or compression,
or both, static or quasi-static testing machines (which may, or may
not, have force-indicating systems). These practices are not
intended to be complete purchase specifications for testing
machines. Testing machines may be verified by one of the three
following methods or combination thereof:

Use of standard weights,

Use of equal-arm balances and standard weights, or

Use of elastic calibration devices.

NOTE 1-These practices do not cover the verification of all
types of testing machines designed to measure forces, for example,
the constantrate- of-loading type which operates on the
inclined-plane principle. This type of machine may be verified as
directed in the applicable appendix of Specification D 76.

The procedures of 1.1.1-1.1.3 apply to the verification of the
force-indicating systems associated with the testing machine, such
as a scale, dial, marked or unmarked recorder chart, digital
display, etc. In all cases the buyer/owner/user must designate
the force-indicating system(s) to be verified and included in the
report.

Since conversion factors are not required in this practice,
either inch-pound units, SI units, or metric values can be used as
the standard.

Forces indicated on displays/printouts of testing machine data
systems-be they instantaneous, delayed, stored, or
retransmitted-which are verified with provisions of 1.1.1, 1.1.2,
or 1.1.3, and are within the 61 % accuracy requirement, comply with
Practices E 4.

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