ISO 148-2:2016 covers the verification of pendulum-type impact testing machines, in terms of their constructional elements, their overall performance and the accuracy of the results they produce. It is applicable to machines with 2 mm or 8 mm strikers used for pendulum impact tests carried out, for instance, in accordance with ISO 148-1. It can be applied to pendulum impact testing machines of various capacities and of different design. Impact machines used for industrial, general or research laboratory testing of metallic materials in accordance with this part of ISO 148 are referred to as industrial machines. Those with more stringent requirements are referred to as reference machines. Specifications for the verification of reference machines are found in ISO 148-3. ISO 148-2:2016 describes two methods of verification. a) The direct method, which is static in nature, involves measurement of the critical parts of the machine to ensure that it meets the requirements of this part of ISO 148. Instruments used for the verification and calibration are traceable to national or international standards. b) The indirect method, which is dynamic in nature, uses reference test pieces to verify points on the measuring scale for absorbed energy. The requirements for the reference test pieces are found in ISO 148-3. A pendulum impact testing machine is not in compliance with this part of ISO 148 until it has been verified by both the direct and indirect methods and meets the requirements of Clause 6 and Clause 7. ISO 148-2:2016 describes how to assess the different components of the total energy absorbed in fracturing a test piece. This total absorbed energy consists of - the energy needed to fracture the test piece itself, and - the internal energy losses of the pendulum impact testing machine performing the first half-cycle swing from the initial position. NOTE Internal energy losses are due to the following: - air resistance, friction of the bearings of the rotation axis and of the indicating pointer of the pendulum which can be determined by the direct method (see 6.4.5); - shock of the foundation, vibration of the frame and pendulum for which no suitable measuring methods and apparatus have been developed.
Tämän julkaisun valmistelusta Suomessa vastaa Metalliteollisuuden Standardisointiyhdistys ry, puh. 09 19 231 (vaihde).
Sisällysluettelo
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
3.1 Definitions pertaining to the machine
3.2 Definitions pertaining to energy
3.3 Definitions pertaining to test pieces
4 Symbols and abbreviated terms
5 Testing machine
6 Direct verification
6.1 General
6.2 Foundation/installation
6.3 Machine framework
6.4 Pendulum
6.5 Anvil and supports
6.6 Indicating equipment
7 Indirect verification by use of reference test pieces
7.1 Reference test pieces used
7.2 Absorbed energy levels
7.3 Requirements for reference test pieces
7.4 Limited direct verification
7.5 Bias and repeatability
8 Frequency of verification
9 Verification report
9.1 General
9.2 Direct verification
9.3 Indirect verification
10 Uncertainty
Annex A Measurement uncertainty of the result of the indirect verification of a Charpy pendulum impact machine (informative)
Annex B Measurement uncertainty of the results of the direct verification of a Charpy pendulum impact testing machine (informative)
Annex C Direct method of verifying the geometric properties of pendulum impact testing machines using a jig (informative)
ISO 148-1:2009 Metallic materials -- Charpy pendulum impact test -- Part 1: Test method
ISO 148-3:2008 Metallic materials -- Charpy pendulum impact test -- Part 3: Preparation and characterization of Charpy V-notch test pieces for indirect verification of pendulum impact machines
ISO 148-1:2009 Metallic materials -- Charpy pendulum impact test -- Part 1: Test method
ISO 148-3:2008 Metallic materials -- Charpy pendulum impact test -- Part 3: Preparation and characterization of Charpy V-notch test pieces for indirect verification of pendulum impact machines