Superseding
Chinese Name	��ߴ����ϵͳ�����������У׼�淶
English Name
Chinese Standard Classification
Professional Classification
ICS Classification
Issued on	March 17, 2008
Implemented on	October 1, 2008
Abolished on
Issued by	Commission of Science, Technology and Industry for National Defence
Chinese Pages
Word Count	3,000 words

1  Scope

    This calibration specification specifies the metrological characteristics, calibration conditions, calibration item, calibration method, the processing of calibration results and time interval of recalibration for large scale coordinate measurement system-laser tracker (hereinafter referred to as laser tracker)
    This calibration specification is applicable to newly-manufactured and repaired laser trackers as well as those in use.

2  Normative References

    The following standards contain provisions which, through reference in this calibration specification, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, the parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards. For undated references, the latest edition of the normative document referred to applies.
    JJG 718  Temperature Indication Controller
    JJG 739  Double Frequency Laser Interferometer
    JJG 875  Verification Regulation of Digital Pressure Gauges

3  General Description

3.1  Usage
    Laser tracker is large scale coordinate measurement system with spherical coordinate. It is mainly used for large scale coordinate measurement and the measurement of large member scale as well as shape and position errors, and for the continuous and static measurement of moving and static members.
3.2  Principle
    The original measuring value of laser tracker shall be expressed by spherical coordinate. Laser tracker mainly consists of three parts, i.e. two angle measuring unit and one distance measuring unit. Angle measuring unit is two angle coders, Distance measuring unit is a single-beam laser interferometer, which conducts measurement by contacting the measured object through spherical target reflector. A four-quadrant position sensitive detector (PSD) is used for tracing, and motor is controlled by PSD to keep laser beam always point to the center of target reflector.
3.3  Structure
See Figure 1 for the structural diagram of laser tracker, and see c) in Figure 1 for specific structure.