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Renishaw Probe SP25

Renishaw Probe SP25 | metrology equipment

Only 25mm in diameter, and with a comprehensive range of scanning and touch- trigger modules, the SP25M is the world's most compact and versatile scanning Renishaw probe system.

The SP25M comprises two sensors in a single housing. Users can switch between a choice of four scanning modules (which can carry M3 styli with lengths from 20 mm to 400 mm) and an adaptor module that is compatible with Renishaw's TP20 range of probe modules. This capability enables scanning and touch-trigger probing in a single probe system.

The SP25M's compact size and auto-joint mount makes it compatible with the PH10M/MQ and PH6M Renishaw probe heads. It can also be mounted on a multi-wired extension bar assisting with deep penetration of part features. Together, the combination of long styli length and extension bars permit excellent reach and access to all complex part features. For full details of the technology in SP25M, refer to the SP25M Technical Paper.


Renishaw Probing SP25 | metrology equipment

Features and benefits of our Renishaw Probes

  • World's smallest scanning probe at only 25 mm in diameter
  • Excellent metrology equipment- isolated optical sensing and 3rd order polynomial compensation nominal compensation
  • Four modules provide optimal performance across a range of stylus lengths (up to 400 mm)
  • Two sensors in one - scanning and touch-trigger
  • Crash protection and simple cmm stylus changing
  • Fast and efficient probe calibration cycle
  • Ideal for profile and form measurement
  • Suitable for use on PH10M motorized indexing head for improved flexibility and shorter scanning cycle tiSimple and robust design for greater reliability - no motors or locking mechanisms.

How the Renishaw Probe SP25 Works

Without doubt, SP25M stands apart from other scanning probes available due to its high scanning accuracy, even with long styli. Incorporation of Renishaw's 'isolated optical metrology' design principles allows SP25M to remarkably counter most of the traditional deterioration in performance seen in other types of scanning probe as cmm stylus length increases. The key innovations, which achieve this, are described below while the diagram illustrates the general internal arrangement of the sensor.

The probe body houses the probe electronics and two of the three components which comprise the 'isolated optical metrology' transducer system, these being a pair of infrared beam sources.

Renishaw Probing SP25 | metrology equipment
Renishaw Probing SP25 | metrology equipment

Lasers and Mirrors in our Metrology Equipment

The scanning module houses the remaining components of the isolated optical metrology system which are a patented pivot spring motion system with an integral pair of reflective concave mirrors. ctive concave mirrors.

The pivoting motion system comprises two diaphragm springs and a ferrofluid damping system. One spring allows movement in all directions whilst the other (pivot) spring is stiff in (probe) X & Y but allows movement in Z.

The reflective mirrors are integrally mounted to the motion system and therefore move directly with stylus deflection. In operation, the IRED beams, originated in the probe body, are directed onto the mirrors inside the scanning module. These beams are then focused and reflected back onto the PSDs in the probe body and can then be translated into spatial measurement coordinates.

The physical arrangement of the motion and optical system has been carefully designed to ensure SP25M achieves maximized transducer gain (i.e. best IRED beam utilization of the PSD area) as the stylus deflects (pivots) within its operating range.

This is a crucial part of SP25M's design principle and is the reason for having four dedicated scanning modules. To explain further;
What if just one module was used (say SM25-2 with its 50-105 mm design range) and an attempt was made to use an excessive cmm stylus length of say 150 mm. For a given stylus deflection (say the maximum of 0.5 mm) the result would be that the swept area of the IRED beams across the PSD reduces and directly affects transducer gain, significantly compromising accuracy. This is due to the increased length from tip to pivot spring which decreases the relative pivot angle.

Conversely, if an attempt was made to use too short a cmm stylus on the same module, say just 25 mm. The same deflection would result in excessive pivot motion which may over-travel the operating range of the PSDs, and may also cause breakout of the stylus holder kinematic joint. Again, the affect on accuracy would be disastrous!

Renishaw Probing SP25 | metrology equipment

The four modules have therefore been designed specifically such that with the shortest specified cmm stylus the larger angular rotation will give peak transducer performance. Also, by limiting the maximum stylus length that can be used, performance is always maintained within an optimum zone for our metrology equipment.

The operating range of each module is at least 0.5 mm radius in all directions, in all orientations, (i.e. this is the range if using heaviest recommended stylus configuration).

Low stylus contact forces are achieved and this is related to the actual stylus length used within the specified module range - for example ~0.2 N/mm when using shortest stylus up to ~0.6 N/mm when using longest.

The low Renishaw probe mass allows a low spring rate whilst retaining improved dynamic response over traditional scanning probe designs. The improved dynamics of SP25M allows faster scanning measurements to be taken.

SP25M is calibrated using Renishaw's non-linear method utilizing a third-order polynomial equation and by taking specified scan paths (including bidirectional) over the datum sphere.

Renishaw probes and styli represent the best in metrology innovation and application. That’s why, other than our own scan heads, Renishaw probes drive every measuring system we sell.  The creators of 5-axis technology completely evolved metrology with the REVO scan head and offer the same level of head articulation in the versatile PH20 tactile touch probe.  We’re so dedicated to only using the best metrology sensors and sensor systems that we will match or beat any price on Renishaw probes you find.  For more information about finding the correct Renishaw probe for your task or to learn about other Renishaw aftermarket products please call us at 248.295.4300 or email [email protected]


Renishaw Probing SP25 | metrology equipment


Renishaw Probe SP25

Wenzel America, Ltd.
28700 Beck Rd.
Wixom, MI 48393
Phone 248.295.4300