GB/T 39543-2020 Design and metrological characteristics of dial test indicators (lever type)Design and metrological characteristics of dial test indicators (lever type)
1 Scope
This standard specifies the most important design and metrological characteristics of dial test indicators (lever type).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 24634-2009 Geometrical Product Specifications (GPS) - General concepts and requirements for GPS measuring equipment (ISO 14978:2006, IDT)
ISO 14253-1:1998 Geometrical Product Specifications (GPS) - Inspection by measurement of workpieces and measuring equipment - Part 1: Decision rules for proving conformance or non-conformance with specifications
ISO 14253-2 Geometrical Product Specifications (GPS) - Inspection by measurement of workpieces and measuring equipment - Part 2: Guide to the estimation of uncertainty in GPS measurement, in calibration of measuring equipment and in product verification
ISO/IEC Guide 98-3 Uncertainty of measurement - Part 3: Guide to the expression of uncertainty in measurement (GUM:1995)
ISO/IEC Guide 99 International vocabulary of metrology - Basic and general concepts and associated terms (VIM)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 24634, ISO 14253-1, ISO 14253-2 and ISO/IEC Guide 99 as well as the following apply.
3.1
dial test indicators (lever type)
measuring instrument in which the displacement of a pivoting stylus is transmitted and magnified by suitable mechanical means to a pointer which rotates in front of a circular scale
4 Design characteristics
4.1 General design features
4.1.1 The general design and workmanship of the dial test indicator shall be such that its metrological characteristics comply with the requirements of this International Standard under all orientations of operation.
4.1.2 Dial test indicators indicate displacement in a direction normal to the axis of the stylus, and in the same plane as the rotational direction of the stylus, unless otherwise stated. See Figure D.1 as an example. If used at some other angle, a correction shall be made (see Annex D).
4.1.3 Dial test indicators shall be capable of measuring when the stylus is displaced in either direction from its rest position.
Note: Some dial test indicators have the ability to measure in both directions without external adjustments and some dial test indicators are provided with a bias lever to change the measuring direction.
4.2 Type
Dial test indicators are commonly manufactured in three types [see Figure 1 a), b) and c)]. These types have the following names:
— Type S, Standard, where the dial face is mounted on the body of the dial test indicator, in a plane perpendicular to the plane in which the stylus moves;
— Type H, Horizontal, where the dial face is mounted on the body of the dial test indicator, in a plane parallel to the plane in which the stylus moves;
— Type V, Vertical, where the dial face is mounted at the end of the dial test indicator opposite that of the stylus.
Foreword II
1 Scope
2 Normative references
3 Terms and definitions
4 Design characteristics
4.1 General design features
4.2 Type
4.3 Nomenclature
4.4 Dovetail mounting
4.5 Dial and pointer
4.6 Stylus
4.7 Zero adjustment
4.8 Design characteristics (manufacturer's specification)
5 Metrological characteristics
5.1 Maximum permissible error (MPE) and maximum permissible limit (MPL) for a number of metrological characteristics
5.2 Stylus
5.3 Measuring forces
6 Proving of conformance with specification
6.1 General
6.2 Measurement standards for calibration of metrological characteristics
7 Marking
Annex A (Informative) Examples of a diagram of errors of indication
Annex B (Informative) Example of data sheet for dial test indicators
Annex C (Informative) Calibration of metrological characteristics
Annex D (Informative) Notes on use
Annex E (Informative) Relation to the GPS matrix model
Bibliography
