Profile Roughness

The Profile Roughness tool calculates multiple measurements of profile roughness according to different industry standards, including the following:

ISO 21920

ISO 4287

ASME B46.1

JIS B0601

ISO 13565

ISO 12085

VDA 2006

VDA 2007

Parameters and measurements differ with standards. Choose the standard appropriate for your application.

There cannot be a large invalid point range for Profile roughness. Use the region to restrict the valid range in the tool for the calculation.

Because the accuracy of a roughness measurement is limited by the X resolution of a sensor, this tool is typically only used on confocal sensors, whose high resolution is better suited for roughness applications.

For information on adding, managing, and removing tools, as well as detailed descriptions of settings common to most tools, see Tool Configuration.

Inputs

You configure the tool's inputs in the expandable Inputs section.

To use a measurement as an anchor, it must be enabled and properly configured in the tool providing the anchor. For more information on anchoring, see Measurement Anchoring.

Inputs
Name	Description
Enable Batching	When Enable Batching is checked, the tool takes an array as input and processes each profile in the array individually. There is no limit to the size of the array, other than the processing limitations of the sensor. For more information on arrays, batching, and aggregating, see Arrays, Batching, and Aggregation.
Profile Input	The data the tool applies measurements to or processes.

Parameters

You configure the tool's parameters in the expandable Parameters section.

Note that the tool displays different sets of parameters based on what you set Working Mode to.

Parameters
Parameter	Description
Enable Processing	The calculation starts only when this is checked. Only displayed when Working Mode is set to Check Parameters or Roughness Calibration. (Processing happens automatically in other modes.)
Working Mode	Support the following four working modes: Measurement Check Parameters Reset Parameters Roughness Calibration Before starting the calibration, make sure to remove the old calibration.
Perform Calibration	Performs the calibration. Only displayed when Working Mode is set to Roughness Calibration.
Standard	The standard the tool uses. Some standards change how options in Evaluation Length behave. For some standards, you should follow the recommendations below. ISO 21920 Set All Section Lengths and All Sections (no Averaging). These parameters behave the same with this standard. ISO 4287 Typically, you will set Evaluation Length to "n Section Lengths", and set Section Count to 5. You can also choose "All Section Length" with this standard. ASME B46.1 Typically, you will set Evaluation Length to "n Section Lengths", and set Section Count to 5. If you use a different Evaluation Length option, note that "All Section Lengths" and "All Sections (no Averaging)" are treated the same with this standard. JIS B0601 According to the original definition, “All Section Lengths” should be used. ISO 13565 “Total Profile Length” should be used. ISO 12085 The same as definitions in ISO 4287, or using “Total Profile Length”. VDA 2006 “All Section Lengths” and "All Sections (no Averaging)" are the same. VDA 2007 “Total Profile Length” should be used.
Profile Mode	In the standards, many parameters are also defined in relation to Primary or Waviness Profile. Select the profile mode after setting a standard.
Configuration	Shows when Working Mode is set to "Measurement". See Configuration for details.
Calibration	Shows when Working Mode set to any mode other than "Measurement”
Roughness Target	Shows when Working Mode is “Roughness Calibration”. The parameters are the same as the Configuration group.
Height Parameters	Shows different parameters depending on what you select in Standard. See Height Parameters.
Spatial Parameters	See Spatial Parameters for details.
Hybrid Parameters	See Hybrid Parameters for details.
Material Ratio Parameters	See Material Ratio Parameters for details.
Abbot Functional Parameters	See Abbot Functional Parameters for details.
Abbot Volume Parameters	See Profile Roughness for details.
Element Feature Parameters	See Element Feature Parameters for details.
Motif Parameters	See Motif Parameters for details.

Configuration
Parameter	Description
Use Region Region	Check to set region size.
Fill Gaps Mode	Choose Linear Interpolation to fill gaps in the profile but keep the profile as natural as possible.
Remove Form (Least Squares)	When checked, displays a drop-down containing one of the following: Linear Alignment Polynomial Subtraction: Show “Polynomial Order (<21)” for edit if selected Circular Unwrapping Circle With Nominal Radius: Show “Nominal Radius” for edit if selected.
Remove Outliers	Check to remove outliers from the profile and set Low Threshold and High Threshold. The outliers are defined according to the Sigma Rule in terms of the given percentage multiplied by 1.5.
Remove Waviness	Check to remove the waviness of the profile. Select the filter in Filter Type. The tool provides the following filters according to the ISO 16610 standards series, which allow different filter kernels having different shapes. Choose the filter depending on your application and its sensitivity to the curvature of the waviness. Gaussian Filter: According to ISO 16610-21, ISO 16610-28 If selected, set choose the appropriate option in End Effects (see End Effects). Spline Filter: According to ISO 16610-22, ISO 16610-28. If selected, set Tension Parameter to control how tightly the spline curve fits through the data points. Robust Gaussian Order 0: According to ISO 16610-31, ISO 16610-28. Using Savitzky-Golay ﬁlter coeﬃcients: Retaining the zeros moment means to reduce end eﬀects. Robust Gaussian Order 1: According to ISO 16610-31, ISO 16610-28. Using Savitzky-Golay ﬁlter coeﬃcients: Retaining the ﬁrst moment means to reduce end eﬀects. Robust Gaussian Order 2: According to ISO 16610-31, ISO 16610-28. Using Savitzky-Golay ﬁlter coeﬃcients The cut-off is selected depending on the workpiece surface either according to the valley spacing, or the expected roughness values. At the same time the total evaluation length and the corresponding total profile length are defined according to standards. Deviations are necessary if the workpiece does not allow the required total profile length. If the actual possible total profile length on the workpiece surface is not enough for lt, the number of sampling lengths is reduced accordingly and specified in the drawing. If the actual available total profile length is less than a sampling length, the total height of profile Pt of the primary profile is evaluated instead of Rt or Rz.
Use S-Filter	Check to use a low pass filter with the cut-off wavelength defined in Low Pass Specification.
End Effects	Shows when Remove Waviness is checked. The end effect is the unintended changes in filtration response in the both end sections of an open profile, and the end effect correction methods are according to standard ISO 16610-28. Line Symm. Reflection (LSR) A measured profile is extended by horizontal reflection on the left hand and right hand, respectively. Point Symm. Reflection (PSR) A measured profile is extended by horizontal reflection in conjunction with vertical reflection on the left and right hand respectively. Both reflection lines shall intersect at the respective end point of the profile. Linear Extrapolation (LEX) In the case of linear extrapolation, a least-squares line is fitted to the profile within the left and right end effect regions. Do not Cut Ends (ZPA) Zero padding is a simple method for retaining the total length after filtering the profile. Profile z(x) is padded with zeros over the total length. MountainsMap (Compatible) Tries to make filtering compatible with MMP "Manage End Effect". This setting only applies to Guassian filters. Remove 1/2 at each end No end effects treatment required as the critical regions are not involved in the calculation. Remove 1 cut off each end No end effects treatment required as the critical regions are not involved in the calculation.
Evaluation Length	The evaluation length. One of the following: All Section Lengths The maximum available sections will be used. n section lengths Set the number of sections in Section Count. The effective section number is always limited by the available length. All Sections (no Averaging) All parameters as long as the definition allows are calculated in the entire evaluation length. Total Profile (no averaging) All parameters as long as the definition allows are calculated in the total profile length.
Alignment Mode	Note: The alignment in MountainsMap is left-justified.

Height Parameters
Parameter	Description	Standard
Ra	Roughness average Ra is the arithmetic average of the absolute values of the roughness profile ordinates, in µm.	ISO 21920 ISO 4287 ASME B46.1 JIS B0601 VDA 2006 ISO 13565-2
Rq	RMS roughness Rq is the root mean square average of the roughness profile ordinates, in µm.	ISO 4287 ISO 21920 JIS B0601
Rz	Mean roughness depth Rz is the arithmetic mean value of the single roughness depths Rzi of consecutive sampling lengths, in µm.	ISO 21920 JIS B0601
Rz1max	Maximum height Rz1max is the greatest Rz value from the n sampling lengths lr, in µm.	ISO 4287
Rz(JIS)	The ten point height RzJIS is defined on each sampling length as being the sum of the 5 highest peaks and the 5 deepest holes, divided by 5. The result is expressed in the length unit of the Z-axis, in µm.	JIS B0601
Rz(n)	Maximum height inside the nth section length, in µm.	ISO 4287 JIS B0601
Rmax	Maximum roughness depth Rmax is the largest single roughness depth within the evaluation length, in µm.
Rt	Total height of profile Rt is the distance between the highest peak and the deepest valley of the profile of the total evaluation length ln, in µm.	ISO 21920 ISO 4287 JIS B0601
Rsk	Skewness Rsk is a measure of the asymmetry of the amplitude density curve. A negative skewness value indicates a surface with good bearing properties. (No unit.)	ISO 21920 ISO 4287 JIS B0601
Rku	Kurtosis Rku is a measure of the peakedness of the amplitude density curve. (No unit.)	ISO 21920 ISO 4287 JIS B0601
Rp Rpm	Rp is the height of the highest profile peak of the roughness profile within one sampling length. According to ASME, the Rp mean value (average calculated over the evaluation length) is called Rpm. Both in µm.	ISO 21920
Rv	Rv is the depth of the deepest profile valley of the roughness profile within one sampling length, in µm.	ISO 21920
Rz	The sum of Rp + Rv is the single roughness depth Rzi, in µm.	JIS B0601
Rzx	Maximum height (peak-to-valley), within a section length, in µm.	ISO 21920
Rc	Mean height of profile elements A horizontal discrimination of 1% of the sampling length and a vertical discrimination of 10% of Rz are applied to avoid taking into account segments with outlying values due to noise. In µm.	ISO 4287 JIS B0601
Rp1max	Maximum local profile peak height Rp1max is the Maximum of Rpi values which are calculated within a sampling length, in µm.	ISO 4287 JIS B0601
Rv1max	Maximum local profile valley depth Rv1max is the Maximum of Rvi values which are calculated within a sampling length, in µm.	ISO 4287 JIS B0601
Rz1max	Maximum local height of the profile Rz1max is the Maximum of Rzi values which are calculated within a sampling length, in µm.
Rpt	Maximum hill height, in µm.	ISO 21920
Rvt	Maximum dale depth, in µm.	ISO 21920

Spatial Parameters
Parameter	Description	Standard
Ral	Autocorrelation length Ral is the horizontal distance of the autocorrelation function (tx) which has the fastest decay to a specified value s, with 0 < s < 1. The default value for s in the software is 0.2. This parameter expresses the content in wavelength of the surface. A high value indicates that the surface has mainly high wavelengths (low frequencies). In mm.	ISO 21920
Rsw	Dominant spatial wavelength Rsw is the wavelength corresponding to the largest value of the FFT. In mm.	ISO 21920
WDsm	Mean horizontal values determined from the amplitude spectrum Size of the profile elements (mean period length of the dominant waviness). In mm.	VDA 2007
WDc	Average of the heights of the profile elements within the evaluation length, in µm.	VDA 2007
WDt	Vertical difference between the highest and lowest point of the WD profile within the evaluation length, in µm.	VDA 2007

Hybrid Parameters
Parameter	Description	Standard
Rdq	Root mean square gradient Rdq is the root mean square value of the ordinate slopes dZ/dX, within the sampling length, in degrees.	ISO 21920
Rda	Arithmetic mean absolute gradient, in degrees.	ISO 21920
Rdt	Maximum absolute gradient, in degrees.	ISO 21920
Rdl	Developed length Rdl is the Length measured following the profile curve, in mm.	ISO 21920
Rdr	Developed length ratio Rdr is the Ratio between the length measured following the profile curve ("real profile"), and the profile length, expressed as a percentage in excess of 100%.	ISO 21920

Material Ratio Parameters
Parameter	Description	Standard
Rmr	Material ratio Rmr indicates what ratio the totaled length in the material has assumed relative to the evaluation length (in %). The comparison is made in the specified section height c and the total evaluation length ln. The material ratio curve indicates the material ratio as a function of the section height.	ISO 21920 ISO 4287 JIS B0601
Rmr (Rz/4)	Automatic relative material ratio Rmr (Rz/4) is the Material ratio calculated at cut level c = 0.25 Rz, relative to a specified reference level, as a percentage.	ISO 4287 JIS B0601
Rmc	Inverse material ratio Rmc is the height distance between highest level and the cut level c corresponding to a given material ratio, in µm.	ISO 21920
Rdc	Profile section height difference Rdc is the Profile section height difference or bearing height. Gives the vertical distance between two cut levels given by their bearing ratio, in µm.	ISO 4287 ISO 21920 JIS B0601

Abbot Functional Parameters
Parameter	Description	Standard
Rk	Core roughness height Rk is the effective roughness of the profile. It is the height of the roughness profile, without taking into account the elevated hills or the very deep dales, in µm.	ISO 13565-2 ISO 21920
Mr1	Upper material ratio Mr1 is the smallest material ratio at the limits of the roughness core area, as a percentage.	ISO 13565-2 ISO 21920
Mr2	Lower material ratio Mr2 is the highest material ratio at the limits of the roughness core area, as a percentage.	ISO 13565-2 ISO 21920
Rpk	Reduced peak height Rpk is the mean height of the peaks protruding from the roughness core profile, in µm.	ISO 13565-2 ISO 21920
Rpkx Rpk*	Maximum peak height Rpkx is the roughness height of the hills, before area correction, in µm.	ISO 13565-2 ISO 21920
Rvk	Reduced valley depth Rvk is the mean depth of the valleys protruding from the roughness core profile, in µm.	ISO 13565-2 ISO 21920
Rvkx Rvk*	Maximum dale depth Rvkx is the roughness depth of the dales, before area correction, in µm.	ISO 13565-2 ISO 21920
A1	Upper area A1 is calculated as the area of the triangle equivalent to the peaks, µm²/mm.	ISO 13565-2
A2	Lower area A2 is calculated as the area of the triangle equivalent to the holes, µm²/mm.	ISO 13565-2
CV	Crevice volume Equivalent to A2, but expressed in specific units (µm³/µm²). Note: 10 µm³/µm² = 1 mm³/cm², so the CV value is 10 times the A2 value.
APH	Peak height APH is the maximum height of the protruding peaks above the roughness core profile, in µm.	ISO 13565-2
AVH	Valley depth AVH is the maximum depth of the profile valleys below the roughness core profile, in µm.	ISO 13565-2
Rvk/Rk	Valley-core depth ratio Rvk/Rk is the ratio of the reduced valley depth Rvk over the core roughness depth Rk. (No unit.)	ISO 13565-2
Rvq	Valley root-mean square roughness Rvq is the slope of the linear regression calculated on the dale zone, in µm.	ISO 13565-3 ISO 21920
Rpq	Plateau root-mean square roughness Rpq is the slope of the linear regression calculated on the hill zone, in µm.	ISO 13565-3 ISO 21920
Rmq	Material ratio Rmq is the Intersection of both regression lines. Gives information about the depth of the intersection between fine surface finish (plateau zone) and rough surface finish (valley zone), as a percentage.	ISO 13565-3 ISO 21920

Abbot Volume Parameters
Parameter	Description	Standard
Rvm	Material volume Rvm is the volume of material at a material ratio p (as a percentage), in µm³/mm².	ISO 21920
Rvv	Void volume Rvv is the volume of voids at a material ratio p (as a percentage), in µm³/mm².	ISO 21920
Rvmp	Hill material volume Rvmp is the volume of material in the hills, between 0% material ratio and a material ratio p (as a percentage), calculated in the zone above c1, in µm³/mm².	ISO 21920
Rvmc	Core material volume Rvmc is the volume of material in the core, between two material ratios p and q (as a percentage), calculated in the zone between c1 and c2, in µm³/mm².	ISO 21920
Rvvc	Core void volume Rvvc is the volume of void in the core, between two material ratios p and q (as a percentage), calculated in the zone between c1 and c2, in µm³/mm².	ISO 21920
Rvvv	Dale void volume Rvvv is the volume of void in the dales, between a material ratio p (as a percentage) and 100% material ratio, calculated in the zone below c2, in µm³/mm².	ISO 21920

Element Feature Parameters
Parameter	Description	Standard
Rsm	Mean width of the profile elements Rsm gives information about the spacing of motifs (length of the period), in mm.	ISO 4287 ISO 21920 JIS B0601
Rsmx	Maximum profile element width, in mm.	ISO 21920
Rsmq	Standard deviation of the profile element widths Rsmq is the root mean square deviation of widths, in mm.	ISO 21920
Rc	Mean height of the profile elements, in µm.	ISO 21920
Rcx	Maximum height of the profile elements, in µm.	ISO 21920
Rcq	Standard deviation of the profile element heights Rcq is the root mean square deviation of heights, in µm.	ISO 21920
RPc	Peak count parameter RPc corresponds to the number of mean widths of profile elements (XSm) inside a given length (default length 10 mm). (No unit.)	ISO 4287 ISO 21920 JIS B0601

The principle of the Motif standard consists of looking for local peaks and valleys in the primary profile, and associating one valley with the closest preceding and following peaks in order to create a Motif. Several iterative combinations of two Motifs each assure that the most important Motifs, the width of which fall below the limit A, are considered. If not otherwise specified, the default value is A = 0.5 mm. The limit A has a similar function as the cut-off in the Gaussian filtering.

Motif Parameters
Parameter	Description	Standard
R	Mean depth of roughness Motifs R is the arithmetic mean value of the depths Hj of the roughness Motifs within the evaluation length, in µm.	ISO 12085
AR	Mean spacing of roughness Motifs AR is the arithmetic mean value of the lengths ARi of the roughness Motifs within the evaluation length, in mm.	ISO 12085
Rx	Maximum depth of the roughness motifs Rx is the deepest depth Hj within the evaluation length, in µm.	ISO 12085
Rt	Total height of the profile, in µm.	ISO 12085
Kr	Mean slope of the roughness motifs. (No unit.)	ISO 12085
Nr	Number of roughness motifs If the number of roughness motifs is less than 3, only the Rx and the Pt can be computed. (No unit.)	ISO 12085
SR	Standard deviation of the depths of the roughness motifs SR computes the dispersion of the Ri values, in µm.	ISO 12085
SAR	Standard deviation of the spacings of the roughness motifs SAR computes the dispersion of the ARi values, in mm.	ISO 12085
W	Mean depth of waviness Motifs W is the arithmetic mean value of the depths Hj of the roughnes Motifs within the evaluation length, in µm.	ISO 12085
AW	Mean spacing of waviness Motifs AW is the arithmetic mean value of the lengths ARi of the roughness Motifs within the evaluation length, in mm.	ISO 12085
Wx	Maximum depth of the waviness motifs Wx is the biggest of all Wi within the evaluation length, in µm.	ISO 12085
Wte	Total depth of waviness, in µm.	ISO 12085
Kw	Mean slope of the waviness motifs. (No unit.)	ISO 12085
Nw	Number of waviness motifs If the number of roughness motifs is less than 3, only the Wx and the Wte can be computed. (No unit.)	ISO 12085
SW	Standard deviation of the depths of the waviness motifs SW calculates the dispersion of the Wi values, in µm.	ISO 12085
SAW	Standard deviation of the spacings of the waviness motifs SAW calculates the dispersion of the AWi values, in mm.	ISO 12085
Trc	Micro Geometric material ratio Trc is the bearing fraction at a given depth c of the envelope leveled profile, as a percentage.	ISO 12085
HTrc	Micro geometric criterion, in µm.
Rke	Kernel roughness of the envelope leveled profile, in µm.
Rpke	Reduced height of the envelope leveled profile, in µm.
Rvke	Reduced depth of the envelope leveled profile, in µm.

Outputs

Most tools provide measurements, geometric features, or data as outputs.

You configure the Min and Max parameters by expanding the measurement in the Outputs section. In order for a measurement to return a Pass decision, the measurement must be between maximum and minimum values; the range is inclusive.

Measurements
Measurement
Ra Arithmetic average of the absolute values of the roughness profile ordinates. For the other measurements, see the parameter details above.

Data
Type	Description
Extracted Profile	Extraction of the measured profile with the defined region.
Form Removed Profile	Obtained after removal of the nominal form (F-operation).
Roughness Profile	Obtained after filtering including a (high-pass) L-filter (λc) rejecting long wavelengths. When presenting the roughness profile, the mean line is the zero line.