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KOBA-check® Sphere Plate

  • KOBA products are manufactured using special steel stabilized by a long aging process which provides dimensional stability.

  • KOBA-check sphere plates have a symmetrical form that insures stability when used at different temperatures.

  • KOBA-check sphere plates have distortion free support of the spheres which is accomplished by a patented, prism-shaped machined form holding each sphere in its installed position.

  • The main plate is a distortion-free neutral plane, insuring the position between spheres and preventing variation of certified values.

  • Rigid assembly of the support frame guarantees vibration-free use in the vertical position.

  • KOBA-check sphere plates have ceramic spheres specifically arranged on the plate to allow for easy access to the equatorial area in four sectors, permitting the scanning of spheres in hemispherical halves around the poles.

  • KOBA-check sphere plate design permits probing access from both sides of the plate.

  • Access holes, for measuring probes, surround each mounted ball, allowing access to the spheres at various angles to the plate.

  • Ceramic spheres are fixed in a neutral plane.

  • Stable and distortion-free retention of spheres.

  • KOBA-check sphere plates are manufactured to high dimensional accuracy of <0.3µm and a hardness of >1650HV.

  • Insulated handles are provided with all KOBA-check sphere plates. Optional plastic covers can be purchased for further reduction of thermal effects.

  • Purpose built transport containers minimize the risk of damage during transportation.


The periodic monitoring of hand-operated or computer-controlled coordinate measuring machines is carried out on the basis of calibrated mechanical test pieces. Appropriate selection and combination of various test pieces, such as spheres, graduated gage blocks and sphere plates, and their arrangement make it possible to discover the overall measured volume or particular partial measured volumes corresponding to the typical workpiece size and adapt the test to its most important measurement job. The process control is done uniformly in accordance with the nominal data of the test piece. The numeric and graphic evaluation is carried out for each type of test piece with a uniform program and is assessed by trained personnel.

Summary characteristic values give an overview of the current level of accuracy and long-term tendencies. In this way the use of coordinate measuring instruments can be optimized and their downtime minimized without high expense.

To respond to the stiffer requirements for the testing of coordinate measuring instruments, Kolb & Baumann have expanded their supply range (including KOBA-step) by adding the KOBA-check sphere plate. This incorporates virtually all characteristics required of a test device used to monitor coordinate measuring instruments.

Read more about the KOBA-check sphere plate...


Applicable SIC Codes: 3423, 3545, 5049, 5084
Applicable NAICS Codes: 332212, 333515, 423490, 423830

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