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Sharing Excellence
in Industrial Metrology
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Evaluation of measurement results
16 % rule and maximum value rule



Surface texture requirements are defined as tolerance limits. Measurement results of parameters may vary in a range of approx. ±25 %, especially with vertical parameters such as Rz, Rp, Rv, Rt and Rmax.

According to EN ISO 4288 the measurement should be made where the highest values are to be expected, i.e. where the surface quality is the worst (visual determination).

For comparison of measured parameters with defined tolerance limits, one of the following rules is applied:

  • 16 % rule
  • Maximum value rule


16 % rule

If for a parameter the suffix „max“ is not specified, the 16 % rule applies.
Example: Rz 4,0

For requirements that define an upper limit (cf. ISO 1302:2002) for a parameter, the surface is considered “good” if not more than 16 % of the measured parameter values exceed the fixed maximum value.

The surface is considered good if

  • the first measurement value does not exceed 70 % of the defined limit
  • the first three measurement values do not exceed the defined limit
  • not more than one of the first six measurement values exceeds the defined limit
  • not more than two of the first twelve measurement values exceed the defined limit

Otherwise the workpiece is considered „not good“ and has to be rejected.

For requirements that define a lower limit of the parameter, the above described rule applies, referring accordingly to the lower limit and measurement values that fall bellow.


Maximum value rule

When the parameter is identified by the suffix „max“, the maximum value rule applies.
Example: Rzmax 4,0

For requirements that define a maximum value (cf. ISO 1302:2002) for a parameter, the surface is considered “good” if no measured parameter value exceeds the maximum value determined in the drawing or the technical product specification.


Special rule VDA 2006

The 16 % rule is not used. The maximum value rule applies generally even without the “max” index.

VDA 2006 assumes that the dispersion of the parameters is taken into account in the definition of the limit values.geht davon aus, dass die Streuung der Kennwerte bei der Festlegung der Grenzwerte berücksichtigt wird.


Download the roughness parameters leaflet




Eight axes. One measuring system.

Number of the day

The HOMMEL-ETAMIC wavemove with eight fully automatic movable axes can accommodate as many measuring points as required and measure both roughness and contours in a single measuring run.

The HOMMEL-ETAMIC wavemove is integrated directly into the production process as an SPC measuring station. The workpiece can be clamped into the measuring system at any stage of production — wavemove recognizes the workpiece and automatically suggests the predefined measuring points via the operating program.

The design enables manufacturers to move the measuring station straight from the measuring room to the production line — an overhead crane lifts the components and places them directly into the clamping devices in the measuring station, so there is no need to transport the workpiece to a separate measuring room.



To the press release

Information about the HOMMEL-ETAMIC wavemove

To the video


Number of visitors increased by 15 percent


Following a record number of visitors to its exhibition stand, the Industrial Metrology division at Jenoptik looks back at a very successful Control show in Stuttgart. 

In what is fast becoming a tradition, at the beginning of May the metrology industry got together at Control 2014—the world's largest show in the field of quality assurance—to find out about the latest developments in order to determine where to invest in the future. The crucial information, communication and business platform drew more visitors this year than ever before. With 25,445 visitors from 89 countries, the organisers were able to boast a three percent increase over the previous year's already excellent figures.

Significantly more visitors than the previous year 

The number of visitors to the stand in Hall 3 hosted by the Jenoptik Industrial Metrology division actually exceeded even the average increase in visitor numbers. As was evident on the opening day, this was to become a recurrent theme throughout the four day-long event: The total number of visitors we welcomed to our stand increased by noticeably more than 15 percent.


To the highlights of the Control show 2014



Dominant waviness according to VDA 2007

The waviness of a sealing surface is a particular disturbance if the surface profile is dominated by one or more wavinesses. For this reason, the German Association of the Automotive Industry (VDA) specified an evaluation method for sealing surfaces in VDA 2007.

Detailed information on dominant waviness

Download surface parameters flyer




Our Videos on YouTube - 2,721 Views

Jenoptik has joined the social YouTube platform and set up its own channel. 12 films about the Industrial Metrology Division have recently been uploaded.

Jenoptik YouTube Channel

In the December issue of our newsletter "Spotlight on Metrology" we have asked you to "click away". Thank you for 2,721 views.

Your TOP 3 videos:

  • Image
  • Optical surface inspection with the HOMMEL-ETAMIC IPS100
  • Optical shaft measuring systems OPTICLINE


Click here to visit our YouTube channel


Matrix Certified

For the first time, the Bayeux site in France and Schwenningen headquarters in Germany have both been certified in accordance with the EN ISO 9001 standard.

ISO 9001 Certification


More information about the Matrix Certfication


New Jenoptik transducer for pneumatic metrology applications.

Pneumatic technology provides extremely accurate measurement results in dimensional metrology. The new HOMMEL-ETAMIC TPE200 pneumo-electronic transducer from the Jenoptik Industrial Metrology division significantly extends the range of applications for pneumatic metrology.

To the trade press briefing

More information about HOMMEL-ETAMIC TPE200


Jenoptik center innovations and customer-solutions at the 26. Control trade fair

Under the motto “Sharing Excellence in Industrial Metrology” the Industrial Metrology division will be putting the focus on innovations at Control 2012 in Stuttgart from May 8 to 11. The new generation of form measuremt systems will be on show for the first time which even can measure surface roughness and straightness with a single clamping process.,

To the trade press briefing


Overview of our national and international fairs of our division.
Press information
NEWS, press releases and technical articles of our division.