Chu-Shik Kang, Jae Wan Kim, Jong-Ahn Kim, Tae Bong Eom
THREE DIMENSIONAL PROFILE MEASUREMENT OF FOUR-STEP REFERENCE SPECIMENS USING THE FRINGE SCANNING FOURIER TRANSFORM METHOD

A new method of three-dimensional profile measurement of four-step reference specimens is presented. Instead of measuring only the height difference between central points of the two neighbouring surfaces of the specimen, overall profile of the whole specimen can be measured by using the fringe scanning Fourier transform method. The method to determine step height from its surface profile is proposed.

Jorma Jokela, Pasi Häkli, Joel Ahola, Arunas Buga, Raimundas Putrimas
ON TRACEABILITY OF LONG DISTANCES

Geodetic baselines are used to determine traceable lengths in geospatial applications. The 864-m-long Nummela Standard Baseline in Finland is a world-class length standard, which is used in calibrations of the most precise electronic distance measurement (EDM) instruments and in scale transfers around the world. At the moment new instruments based on new technology are developed to measure long distances; this is also a joint research project of the new European Metrology Research Programme (EMRP). As the state-of-the-art, the Nummela Standard Baseline is available for testing the new instruments in field conditions. The baseline was remeasured with the Väisälä interference comparator to 432 m in autumn 2005, and to 864 m in autumn 2007 with better than 0.1 mm standard uncertainty. We present here the results, which again verify the long-term stability of the baseline and excellent repeatability of measurements. We also present an example of a recent scale transfer to a calibration baseline and test field in Lithuania. In addition to national calibration activities, this Kyviškes Calibration Baseline serves in our new research project concerning the scale of precise GPS positioning. Brief introductions to another new geodetic baselines in Austria and Estonia are also given.

Yusuke Kajihara, Takeji Ueda, Patrick Nickels, Susumu Komiyama
PASSIVE TERAHERTZ MICROSCOPY WITH A HIGHLY SENSITIVE DETECTOR

A passive terahertz (THz) microscope has been developed for sensitive imaging of spontaneous THz radiation. The THz microscope consisted mainly of a Ge objective lens, a confocal pinhole, Ge relay lenses, and a highly sensitive THz detector (Charge-Sensitive Infrared Phototransistor, CSIP). Then experimental examinations of the developed microscope were performed. First, THz signals, which were related to the spontaneous thermal radiation, were reasonably obtained. Next a passive THz image was successfully achieved. The lateral resolution of the microscope was derived to be 25 µm, where the depth resolution was derived to be 30 µm. In addition, the lateral resolution was not degraded despite the coverage of GaAs and Si. These results indicate that the THz microscope enables passive imaging with high resolution. This study opens the door to novel THz measurement technology, which can reveal physical and biological phenomena such as molecular motions, biomolecular protein interactions, and semiconductor conditions in their true colors.

Akihiro Oota, Takashi Usuda, Hideaki Nozato, Tamio Ishigami, Tsuneo Kikuchi
ESTIMATION OF UNCERTAINTY CONTRIBUTION OF TRANSVERSE SENSITIVITY AND VIBRATION DISTRIBUTION ON PRIMARY ACCELEROMETER CALIBRATION

Primary accelerometer calibration is carried out under the assumption that a vibration exciter gives a rectilinear motion to an accelerometer to be calibrated. However practical vibration given by the vibration exciter includes parasitic motion such as transverse, rocking, and bending motion. The parasitic motion especially gives two serious effects on primary calibration results, transverse sensitivity effect and vibration distribution effect. Transverse sensitivity effect is caused by an inner product of the vectors of both transverse motion and transverse sensitivity. On the other hand, the vibration distribution effect is caused by motion disturbance and relative difference between acceleration at sensing point of accelerometer and at the spot sensed by the interferometer.
These uncertainty sources have close interaction between vibration exciter and accelerometer, and close interaction between vibration exciter and the laser interferometer, respectively. Therefore, it is very difficult to estimate independently their uncertainty contribution.
In this study, we propose simple methods to estimate uncertainty contribution due to these effects in the primary calibration, respectively. The proposed methods would enable more practical estimation of uncertainty budget.

Chin-Fen Tuan, Fu-Lung Pan, Yi-Ching Lin, Sheau-shi Pan, Chung-Lin Wu
SUB-MILLIGRAM WEIGHT SUBDIVISION AND APPLICATION IN FORCE CALIBRATION OF NANOINDENTER

In this time of flourishing nanotechnology research and the miniaturization of relevant products, the mechanical properties, such as hardness and tensile strength, of relevant materials must be tested in order to ensure product reliability. Because such testing requires the measurement of miniscule forces, relevant testing systems must be traceable to tiny masses of less than one milligram. This paper chiefly investigates induction of the use of a set of weights ranging from 1 mg to 0.1 mg, and describes how 0.5 mg, 0.2 mg, and 0.1 mg weights can be traced from a 1 mg standard weight. This paper explains how such a weight set can be used to calibrate a nanoindenter in micro-forces range and estimate the uncertainties.