ASME B89.4.22-2004 pdf free download.Methods for Performance Evaluation of Articulated Arm Coordinate Measuring Machines
1 SCOPE
The scope of this Standard pertains to the perform- ance evaluation of articulated arm coordinate measuring machines. While any number of rotational joints can be evaluated, the Standard focuses on the more common configurations commercially available today and is limited to seven joints.
The Standard addresses purely manual machines, so no motorized axes are addressed in the current document. While the application of this class of measuring machine continues to grow, at this point in time only contact probes are considered and optical noncontact probes are specifically excluded.
This Standard establishes requirements and methods for specifying and testing the performance of AACMMs. In addition to clarifying the performance evaluation of AACMMs, this Standard seeks to facilitate performance comparisons among machines by unifying terminology, general machine classification, the treatment of environmental effects, and data analysis.
This Standard at- tempts to define the simplest testing methods capable of yielding adequate results for most AACMMs and it is not intended to replace more complete tests that may be suitable for special applications. This Standard provides definitions of terms applica- ble to AACMMs. These definitions are separated into two parts. The first part is a glossary covering technical terms used throughout this and other ASME Standards. The second part defines a number of common machine classifications.
The actual specification is subdivided into three sections: general machine classification, machine environmental requirements, and machine performance. Machine classification includes machine type, measureASME B89.4.22-2004 ment ranges, and rotary axis encoder resolution. Envi- ronmental specification includes thermal response, elec- trical requirements, and vibration sensitivity. Machine performance specification includes effective diameter test, single-point articulation performance, and volumetric performance tests. Within this Standard, performance values are reported as the maximum deviation, the range, and the standard deviation. This is done to bring the Standard more into line with existing national and international standards. In order to clarify the use of this Standard, a short guide on how to use it is included as Appendix A. Productivity is an important consideration in the se- lection of an articulated arm coordinate measuring machine.
There are numerous factors that affect the rela- tive productivity of measuring systems, which include variables attributable to both the measurement system and the workpiece. This Standard does not address methods to specify and evaluate productivity. Produc- tivity should be evaluated with respect to the expected use of the system, including such aspects as software, ergonomics, and the frequency of calibration.
1.1 Contents and Specification Forms Any specification described as complying with this Standard shall include, as a minimum, the following items: (a) a machine classification form (see Fig. 1). If no classification is applicable, the actual configuration shall be described in equivalent detail. (b) an environmental specification form (see Fig. 2). (c) a performance specification form (see Fig. 3).
1.2 Alternatives This Standard allows parts of the environmental test section to be deferred or bypassed and only the per- formance tests to be carried out. This alternative is ac- ceptable only if it is agreeable to both the user and the supplier, and if deferred as specified.
2 DEFINITIONS
2.1 Glossary
2.1.1 Terms. This glossary contains brief definitions of the majority of technical terms used in this Standard. Some of the definitions listed are used in the non mandatory appendices, but are included here for reference purposes. Omissions and clarifications should be reported to ASME (see Correspondence).
ball bar: gage consisting of two highly spherical tooling balls of the same diameter connected by a rigid bar. A ball bar, as used in this Standard, must be sufficiently mechanically rigid that its length is constant during the course of a set of measurements. bias (of a measuring instrument): systematic error of the indication of a measuring instrument.
NOTE: The bias of a measuring instrument is normally estimated by averaging the error of indication over an appropriate number of repeated measurements.
drift: slow change of a metrological characteristic of a measuring instrument.ASME B89.4.22 pdf download.ASME B89.4.22-2004 pdf free download
