| News from the Annual Report 2006 |
• Fundamentals of metrology |
| |
| |
Research cooperation between Sartorius AG and PTB in the field of 1 kg vacuum mass comparators
|
|
Within the scope of a scientific cooperation between Sartorius AG and PTB a 1 kg vacuum mass comparator developed by Sartorius AG in cooperation with the Bureau International des Poids et Mesures (BIPM) and the Technische Universität Ilmenau was installed at PTB. As a result of first measurements standard deviations of < 0.2 µg in air and < 0.1 µg in vacuum could be achieved for the mass comparison of 1 kg stainless steel weights.
- more ...
|
| |
| |
Comparison measurements between primary standards for high-pressure natural gas and atmospheric air
|
|
The primary standards for atmospheric air and high-pressure natural gas were compared by means of sonic Venturi nozzles and the method was verified in a comparison with LNE and NIST.
- more ...
|
| |
| |
Determination of the angular distribution of backscattered particles at the ion accumulation experiment
|
|
A monitor was developed for the measurement of sputtered and reflected particles to determine the mass contribution of particles which are backscattered through the entry hole of the collector at the ion accumulation experiment.
- more ...
|
| |
| |
Broadband Reference Hydrophones for Ultrasound
|
|
Membrane hydrophones developed and manufactured at PTB allow extremely broadband acoustic pressure measurements and the comparison of extended hydrophone calibration techniques.
- more ...
|
| |
| • Metrology for economy |
| |
| |
Calibration of force vector transducers with smallest uncertainties
|
|
Precision force transducers measure the force as a scalar quantity on an axis given by the transducer design. In a research project, transducers shall now be developed which allow the spatial force vector to be measured. PTB develops calibration procedures for this novel measuring technique.
- more ...
|
| |
| |
Alternative calibration method for Laser Doppler Anemometers
|
|
A new, miniaturized calibration method for laser Doppler anemometers is presented which allows narrow measurement points to be accessed. For this purpose, a platinum wire mounted on a carrier is moved linearly through the measurement volume. The movement of the carrier is recorded by interferometry.
- more ...
|
| |
| |
Measurement of sound field in cavitating media by an optical fibre-tip hydrophone
|
|
A fibre-optic technique was applied to measure the sound field in an ultrasonic cleaning vessel under practical conditions.
- more ...
|
| |
| • Metrology for society |
| |
| |
Measuring assembly for testing the influence of mechanical vibrations on sound level measurements
|
|
To check the vibrational sensitivity of sound level meters, a measuring assembly has been set up in which two identical sound level meters are exposed simultaneously to a sound field of constant frequency.
- more ...
|
| |
| |
Extended velocity range for wind tunnel measurements
|
|
The use of laser Doppler anemometers, extended under technical aspects, allowed the velocity range for the calibration of conventional anemometers in wind tunnels to be extended in the range of small velocities.
- more ...
|
| |
| |
PTB organizes workshop for acoustic cavitation in the case of ultrasound excitation
|
|
On November 17 and 18, 2005 the workshop "Cavitation: Description, quantification and standardization for practical applications" was realized under the - surely somewhat provoking - motto "Everybody uses cavitation, but nobody really understands it". On two days, 40 participants from universities, research institutes and manufacturers throughout Germany intensively discussed the fundamentals and applications of this complicated and complex process.
- more ...
|
| |
| • International affairs |
| |
| |
CIPM Key Comparisons for natural gas up to 40 bar completed and published
|
|
The successfully conducted CIPM Key Comparisons for natural gas at high pressure have shown the identity of the harmonized European natural gas cubic metre with the CIPM Key Comparison reference value.
- more ...
|
| |
| |
International comparison measurements for the determination of magnetic properties of mass standards
|
|
Comparison measurements of the CCM Working Group "Mass standards", comprising 17 National Metrology Institutes, for determining the magnetic susceptibility and the magnetization of 1 kg mass standards have been terminated.
- more ...
|
| |
| |
Key comparison confirms top position of pipette testing facility
|
|
PTB has participated in the CIPM key comparison CCM.FF-K4 and has determined the volumes of three 20 liters stainless steel pipettes. The relative uncertainties obtained, < 2·10-5, and particularly the small deviations of the measured volumes from the Key Comparison Reference Values (KCRV) of 1·10-6 (as an average) underpin the top position of the PTB pipette test facility.
- more ...
|
| |
| |
Torque travelling standard shows excellent stability in key comparison
|
|
The first international key comparison CCM.T-K1 in the field of torque piloted by PTB was completed in July 2006. Presently, the results are being assessed and the final report is being prepared. Already now, an outstanding reproducibility in the order of 10-6 can be reported for one of the travelling standards.
- more ...
|
| |
| Back to the Latest scientific news |
| |
