ASTM E74-01

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
An American National Standard
Designation: E 74 – 01
Standard Practice of
Calibration of Force-Measuring Instruments for Verifying the
1
Force Indication of Testing Machines
This standard is issued under the fixed designation E 74; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
4
1. Scope Determine Conformance with Specifications
2.2 American National Standard:
1.1 The purpose of this practice is to specify procedures for
5
B46.1 Surface Texture
the calibration of force-measuring instruments. Procedures are
included for the following types of instruments:
ELASTIC FORCE-MEASURING INSTRUMENTS
1.1.1 Elastic force-measuring instruments, and
1.1.2 Force-multiplying systems, such as balances and small
3. Terminology
platform scales.
3.1 Definitions:
3.1.1 elastic force-measuring device—a device or system
NOTE 1—Verification by deadweight loading is also an acceptable
method of verifying the force indication of a testing machine. Tolerances
consisting of an elastic member combined with a device for
for weights for this purpose are given in Practices E 4; methods for
indicating the magnitude (or a quantity proportional to the
calibration of the weights are given in NIST Technical Note 577, Methods
magnitude) of deformation of the member under an applied
2
of Calibrating Weights for Piston Gages.
force.
1.2 The values stated in SI units are to be regarded as the
3.1.2 primary force standard—a deadweight force applied
standard. Other metric and inch-pound values are regarded as
directly without intervening mechanisms such as levers, hy-
equivalent when required.
draulic multipliers, or the like, whose mass has been deter-
1.3 This practice is intended for the calibration of static
mined by comparison with reference standards traceable to
force measuring instruments. It is not applicable for dynamic
national standards of mass.
or high speed force calibrations, nor can the results of
3.1.3 secondary force standard—an instrument or mecha-
calibrations performed in accordance with this practice be
nism, the calibration of which has been established by com-
assumed valid for dynamic or high speed force measurements.
parison with primary force standards.
1.4 This standard does not purport to address all of the
3.2 Definitions of Terms Specific to This Standard:
safety concerns, if any, associated with its use. It is the
3.2.1 calibration equation—a mathematical relationship be-
responsibility of the user of this standard to establish appro-
tween deflection and force established from the calibration data
priate safety and health practices and determine the applica-
for use with the instrument in service, sometimes called the
bility of regulatory limitations prior to use.
calibration curve.
3.2.2 continuous-reading device—a class of instruments
2. Referenced Documents
whose characteristics permit interpolation of forces between
2.1 ASTM Standards:
calibrated forces.
3
E 4 Practices for Force Verification of Testing Machines
3.2.2.1 Discussion—Such instruments usually have force-
E 29 Practice for Using Significant Digits in Test Data to
to-deflection relationships that can be fitted to polynominal
equations. Departures from the fitted curve are reflected in the
uncertainty (8.4).
3.2.3 deflection—the difference between the reading of an
1
instrument under applied force and the reading with no applied
This practice is under the jurisdiction of ASTM Committee E28 on Mechanical
Testingand is the direct responsibility of Subcommittee E28.01 on Calibration of force.
Mechanical Testing Machines and Apparatus.
Current edition approved Oct. 10, 2001. Published November 2001. Originally
published as E 74 – 47 T. Last previous edition E 74 – 00a.
2 4
Available from National Institute for Standards and Technology, Gaithersburg, Annual Book of ASTM Standards, Vol 14.02.
5
MD 20899. Available from American National Standards Institute, 11 W. 42nd St., 13th
3
Annual Book of ASTM Standards, Vol 03.01. Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E74
3.2.4 loading range—a range of forces within which the
where:
uncertainty is less than the limits of error specified for the
M = mass of the weight,
2
instrument application. g = local acceleration due to gravity, m/s ,
3
d = air density (approximately 0.0012 Mg/m ),
3.2.5 reading—a numerical value indicated on the scale,
D = density of the weight in the sa
...