BS 5868:1980

National foreword
Cooperating organizations
Section one - General
1 Scope
2 Object
3 Definitions related to the measurement or control
      function
3.1 Thickness meter (ionizing radiation)
3.2 Transmission thickness meter (ionizing radiation)
3.3 Beta (gamma) backscatter thickness meter
3.4 X-ray fluorescence thickness meter
3.5 Rated range
3.6 Effective range
3.7 Mass per unit area (surface mass, surface density,
      mass cross-section)
3.8 Influence quantity
3.9 Total measurement area
3.10 Effective measurement area
3.11 Reference conditions
3.12 Rated range of use
3.13 Resolution
3.14 Geometrical resolution length
4 Definitions related to the apparatus
4.1 Measuring head
4.2 Electrical measuring sub-assembly
4.3 Traversing mechanism
4.4 Measuring gap
4.5 Pass line
4.6 Reference pass line
4.7 Sample profile error
4.8 Pass line error
4.9 Mean response time
4.10 Mean settling time
4.11 Electrical instability
4.12 Overall radiometric instability
Section two - General requirements
5 General
5.1 Thickness meters in general
5.2 Traversing transmission thickness meters
Section three - Test requirements
6 Determination of the limits of error
6.1 Test procedure
6.2 Performance characteristics
6.3 Influence quantities
7 Other performance characteristics
7.1 Mean settling time
7.2 Resolution
7.3 Geometrical resolution length
7.4 Mean response time
7.5 Measurement areas
Appendix A
National appendix. Electrical measuring instruments
                   utilizing radioactive sources (IEC
                   476)