Testing machines that apply and indicate force are in general use in many industries. Practices E 4 has been written to provide a practice for the force verification of these machines. A necessary element in Practices E 4 is the use of devices whose force characteristics are known to be traceable to national standards. Practice E 74 describes how these devices are to be calibrated. The procedures are useful to users of testing machines, manufacturers and providers of force measuring instruments, calibration laboratories that provide the calibration of the instruments and the documents of traceability, and service organizations that use the devices to verify testing machines.

1.1 The purpose of this practice is to specify procedures for the calibration of force-measuring instruments. Procedures are included for the following types of instruments:

1.1.1 Elastic force-measuring instruments, and

1.1.2 Force-multiplying systems, such as balances and small platform scales. Note 1Verification by deadweight loading is also an acceptable method of verifying the force indication of a testing machine. Tolerances for weights for this purpose are given in Practices E 4; methods for calibration of the weights are given in NIST Technical Note 577, Methods of Calibrating Weights for Piston Gages.

1.2 The values stated in SI units are to be regarded as the standard. Other metric and inch-pound values are regarded as equivalent when required.

1.3 This practice is intended for the calibration of static force measuring instruments. It is not applicable for dynamic or high speed force calibrations, nor can the results of calibrations performed in accordance with this practice be assumed valid for dynamic or high speed force measurements.

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.