INTERNATIONAL STANDARD ISO 16859-2

Metallic materials — Leeb hardness test — Part 2: Verification and calibration of the testing devices

ISO 16859 consists of the following parts, under the general title Metallic materials —— Leeb hardness test:

ISO 16859-1 Metallic materials — Leeb hardness test — Part 1: Test method

ISO 16859-2 Metallic materials — Leeb hardness test — Part 2: Verification and calibration of the testing devices

ISO 16859-3 Metallic materials — Leeb hardness test — Part 3: Calibration of reference test blocks

Contents

Foreword

1 Scope

2 Normative references

3 General conditions

4 Direct verification

  4.1 General

  4.2 Calibration parameters

  4.3 Verification of mass and geometry of impact body

  4.4 Verification of geometry and hardness of indenter ball

  4.5 Verification of geometry of support ring

  4.6 Verification of impact velocity

  4.7 Indirect verification of instrument

5 Indirect verification

  5.1 General

  5.2 Procedure

  5.3 Variation coefficient (V)

  5.4 Error of test instrument

  5.5 Measurement uncertainty

6 Intervals between verifications

7 Verification report/calibration certificate

Annex A (informative) Measurement uncertainty of calibration results of Leeb hardness testing instrument

Annex B (informative) Direct verification of single coil instrument

Bibliography

1 Scope

This part of ISO 16859 specifies methods for direct and indirect verification of test instruments used for determining Leeb hardness in accordance with ISO 16859-1, and also describes when these two types of verification are to be performed.

The direct verification involves checking that individual instrument performance parameters fall within specified limits, whereas the indirect verification utilizes hardness measurements of reference test blocks, calibrated in accordance with ISO 16859-3, to check the overall performance of the instrument for testing in the direction of gravity. The indirect method can be used on its own for the periodic performance checking in service.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 16859-1, Metallic materials — Leeb hardness test — Part 1: Test method

ISO 16859-3, Metallic materials — Leeb hardness test — Part 3: Calibration of reference test blocks

ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method

3 General conditions

Before a Leeb hardness testing instrument is verified, the instrument shall be checked to ensure that it is properly set up and operating in accordance with the manufacturer’s instructions.

Especially it should be checked that

a) the impact body is correctly installed in the guide tube,

b) the support ring is mounted tightly to the bottom of the impact device,

c) cables are correctly connected, if applicable, and

d) the settings of the indicating unit are correct.