Confocal 3-D Microscopy

A selection of historical results from the work that led to my dissertation.

Reference for comparison of confocal white light microscopy with tactile sensors
A letter from Dr. Hillmann, Head of the Laboratory for Surfaces of the Physikalisch-Technische Bundesanstalt PTB (1995), concerning the results within the scope of my dissertation.

PTB-RN-4058/01

Fig. 1: Comparison on a PTB roughness standard 4058/01 Level 3 (Ra = 1.45 µm). The lower blue profile shows the microscopic measurement, the upper red profile the tactile reference measurement.

Fig. 2-4: Comparison on a PTB roughness standard. 4058/01 level 1 (Ra = 0.20 µm). The red profiles in Fig. 2 show the tactile reference measurement, above as the overall profile, below as a section.

Fig. 3: shows the equivalent microscopic measurement. Fig. 4 shows the profile comparison between tactile and microscopic measurement.

PTB-TE-4060

Fig. 1: shows the measurement at the deepest groove (9 µm) of the PTB depth setting standard.

Fig. 2: shows the measurement on a shallow groove (0.6 µm) of the PTB depth setting standard. The grooves of the PTB depth setting standard are lapped into a polished glass block. Lapping grooves of a few 10 nm depth are clearly visible in the shallow groove.

Sheets

Confocal 3D microscopic measurements on four differently textured sheets.

Form

Confocal 3D microscopic measurements on a steel pin (left image) and a Vickers hardness indentation (right image).

Glasses

Confocal 3D microscopic measurements on different textured glass surfaces.

Microstructures

Confocal 3D microscopic measurements on various microstructures.

Paper

Confocal 3D microscopic measurements on different papers.

Fig. 1: Long-fiber white paper

Fig. 2: Recycled paper

Fig. 3: Transparent drawing paper

Fig. 4: Banknote paper