losing the gap with tactile probe accuracy

The LC15Dx is a viable alternative to a tactile probe for an increasing number of high precision CMM applications.

Thanks to new solid state laser scanner technology, an innovative calibration method and high quality Nikon lens, the LC15Dx is closing the gap between laser scanner and tactile probe accuracy. In tests comparable to ISO 10360-2 MPE_P and ISO 10360-5 MPE_AL the LC15Dx achieved the accuracy associated with using a tactile probe on a CMM. Unlike a tactile probe, the LC15Dx uses non-contact 3D laser triangulation to measure the surface directly and eliminate probe compensation errors. The uncertainty and delay caused when a laser scanner is used before it has reached operating temperature, has been eliminated by a thermal stabiliser mounted inside the scanner body.

The LC15Dx probing error of 1.9 µm (0.000075 in) mirrors the accuracy expected when using a CMM fitted with a tactile probe. Likewise the Nikon scanner probing error test mirrors, as closely as possible, the equivalent ISO 10360-2 MPE_P tactile probing error test, as depicted in the diagram to the right. Probing error determines the level of measurement uncertainty when measuring Form using a single probe head position. Normal convention dictates measurement uncertainty should not exceed 30% of the design tolerance of the measured part.

The LC15Dx multi-stylus test accuracy of 3,9 µm (0.00015 in), often referred to as “real-world-accuracy”, mirrors the accuracy expected when using a CMM fitted with an indexing head and tactile probe. Once again the Nikon scanner multi-stylus test mirrors, as closely as possible, the equivalent ISO 10360-5 MPE_AL indexing head and tactile probe multi-stylus test, as shown in the diagram to the left. The multi-stylus test determines the level of measurement uncertainty when measuring the location using multiple probe head positions.

Scanning glossy or multi-material surfaces

Nikons unique ESP3 technology maintains accuracy, speed and data quality by intelligently adapting the laser settings for each measured point in real-time.

A wider range and mixture of surface materials, finishes, colours and transitions can be measured more efficiently without user interaction, manual tuning and part spraying, including small and fragile parts.

Unwanted reflections from very shiny surfaces are neutralised by an advanced software filter while changes in ambient light are absorbed by a high grade daylight filter.

For the most extreme parts and materials manual laser settings are also available should they be necessary.

Measurement at the speed of light!

Measuring the entire part or complete features, without compromising on throughput, is not a problem when you can measure 70,000 points at the speed of light every second.

As the LC15Dx passes over the workpiece, a laser line is projected onto the surface. The line contains hundreds of measurement points spaced 0.022mm (0.0008) apart. Triangulation between the laser, workpiece and sensor is used to determine the position of the workpiece in 3D space. The user has full control over the amount of measured data by varying the distance between the laser lines.

Suitable for high precision parts and small geometry

The LC15Dx provides significant benefits for a wide variety of high precision parts and geometry, including small details, semi-rigid parts and the more demanding materials:

Precision moulding Measure small, soft and fragile parts

Medical implants Inspect complex freeform geometry

Turbine blades Laser scanning eliminates probe tip compensation

Multi-sensor CMM : Combine laser scanning with tactile probing

In some cases a single sensor technology is insufficient for measuring all the features.

The LC15Dx can be combined with an optional tactile probe to create a versatile multi-sensor CMM. Depending on the application both technologies can be used independently or together in the same inspection program.

Fully automatic sensor changing is possible with the addition of an optional change and storage rack which is mounted on the table of the CMM.

Enhance the capability of your current CMM

Retrofitting your current CMM with an LC15Dx is a cost-effective solution. The retrofit integrates with the existing CMM controller hardware and compatible probe system to provide a versatile multi-sensor CMM offering both non-contact and touch probe inspection.

LC15Dx retrofit kits are available for the follow CMM controller systems.

• Deva
• LK
• Hexagon Brown & Sharpe
• Mitutoyo
• Hexagon DEA
• Renishaw
• Hexagon Sheffield
• Wenzel
• Zeiss

Probing error (MPEp)1	1.9 µm (0.000075” )
Ball bar length (MPEE)2	4µm +L/350mm (0.00016  +L/13.78“)
Multi-stylus test (MPEAL)3	3.9 µm (0.00015“)
ISO Probing form error4	7 µm (0.00027“)
ISO Probing size error all5	15 µm (0.000591”)
ISO Probing dispersion value6	7,6 µm (0.000299“)
ISO Cone angle7	100°
Scanning speed (approx.)	70,000 points/sec
Resolution (point spacing)	22 µm (0.00087“)
Points per line(approx.)	900
Measuring temperature range	18-22°C (64.4-71.6° F)
Operating temperature range	10-40°C (50-104° F)
Weight	370 g (0.82 lbs)
Ingress Protection	IP30
Laser safety	Class 2
Enhanced Scanner Performance	ESP3
Daylight filter	Yes
Probe head compatibility	PH10M, PH10MQ, CW43, PHS

All accuracy specifications valid for a CMM with an accuracy of 2µm + L/350 or better using manufacturer supplied test sphere
¹Nikon Metrology test comparable to EN/ISO 10360-2 MPE_P using 1 sigma sphere fit.
²Nikon Metrology test comparable to EN/ISO 10360-2 MPE_E
³Nikon Metrology test comparable to EN/ISO 10360-5 MPE_AL

Accuracy specifications according ISO 10360-8:2013:
4 P_{Form.Sph.1x25:Tr:ODS,MPE} : Maximum probing form error using 25 representative points in translatory scanning mode
5 P_{Size.Sph.All:Tr:ODS,MPE} : Maximum probing size error All using all measured points in translatory scanning mode
6 P_{Form.Sph.D95%:Tr:ODS,MPL} : Maximum probing dispersion value using 95% of the measured points in translatory scanning mode
7 Cone angle : Region of sphere on which the measured points are selected