ISO 12179 pdf download – Geometrical Product Specifications (GPS)-Surface texture:Profile method -Calibration of contact (stylus) instruments

ISO 12179 pdf download – Geometrical Product Specifications (GPS)-Surface texture:Profile method -Calibration of contact (stylus) instruments.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 3274. ISO 4287, ISO 14253-1, VIM Isorne of which are reproduced below (without their notes) for conveniencej. GUM. and term and definition 3.2, apply.
3.1
calibration
set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring instrument or measuring system, or values represented by a material measure or a reference material, and the corresponding values realized by standards
[VIM 6.11)
3.2
task related calibration
set of operations which estabhsh, under specified conditions, the relationship between values of quantities indicated by a measuring instrument and the corresponding known values of a limited family of precisely defined measurands which constitute a subset of the measuring capabilities of the measuring instrument
3.3
adjustment (of a measuring instrument)
operation of bringing a measuring instrument into a state of performance suitable for its use
LVIM 4.30)
3.4
(measurement) standard etalon
material measure, measuring instrument, reference material or measuring system intended to define, realize, conserve or reproduce a unit or one or more values of a quantity to serve as a reference
[VIM 6.1]
NOTE In ISO 5436:1985, •measurement standards were relerred to as caIibration specimens”.
3.5
uncertainty of measurement
parameter, associated with the result of a measurement, that characterizes the dispersion of the values that could reasonably be attributed to the measurand
[VIM 3.9)
3.6
traceabIlity
property of the result of a measurement or the value of a standard whereby it can be related to stated references, usually national or international standards, through an unbroken chain of comparisons all having stated uncertainties
— The best fit procedure (i.e. least squares, minmum zone. etc.). used in the calibration of the measurement standard, shall be used.
7.2 Evaluation of the residual profile
Traverse the optical flat. Determine the residual profile and calculate the surface texture parameters Pt and Pq. For task-related calibration, calibrate in accordance with the measuring conddions for each required measurement. For example, when measuring a roughness measurement standard, a cut-off wavelength Ac = 0,8 mm and a cut-oft ratio of 300:1, making a total evaluation length of 4 mm, are used. The measured values of Ra and R: shall be indicated in the calibration certificate for the instrument,
7.3 Calibration of the vertical profile component
7.3.1 Overall objective
Traverse the groove(s) of the depth measurement standard. From the primary profile determine the respective
deviations from the value stated in the appropriate calibration certificate.
7.3.2 Procedure
Measure the groove(s) in profile sections within the calibrated area of the measurement standard (see Figure 1). Traverse the groove(s) individually and determine the depth of the groove(s) according to the calibration procedure supplied with the depth measurement standard. State the deviation of the (mean) value [obtained from the measured value(s)) from the figure given in the calibration certificate of the depth measurement standard.
Alternatively, it a depth measurement standard is not available, wring two gauge blocks, juxtaposed. onto an optical flat. Traverse across both gauge blocks and determine the respective height difference from the total profile. State the deviation in the measured height difference from the difference in heights calculated from the values stated in the calibration certificates of the gauge blocks.
7.4 Calibration of the horizontal profile component
7.4.1 Overall objective
Traverse the spacing measurement standard. Determine the respective deviations from the wavelength parameters
staled in the calibration certificate.
7.4.2 Procedure
Perform measurements on the spacing measurement standard, distributed over the measurement surface. An example of a measuring plan is given in Figure 2. Calculate the anthmetical mean for the primary parameter PSrn. Record the deviations from the values stated in the calibration certificate.
7.5 Calibration of the profile co-ordinate system
7.5.1 Overall objective
Traverse the inclined optical flat, sphere or prism. Determine Pt of the respective deviations from the least squares best fit of the form of the specimen.