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Development of a Transportable Calibration Device for Simple Measuring Instruments


For most simple measuring instruments (SMI) as micrometers, calipers and dial gauges no well-suited calibration devices exist. These SMI are calibrated using material measures or using expensive instruments like coordinate measuring machines. A new device is to be developed which can also be applied to these SMI. Furthermore the device is aimed at to be used under laboratory as well as under workshop and production conditions. Another advantage of the new device is the replacement of a great number of material measures in the calibration offices, which are normally used to carry out calibrations. Furthermore it is easy to increase the number of calibration points to get more security for the maximum permissible error carried out at the calibration using the new device.
The SMI to be calibrated have relative maximum permissible errors in the range of 10-3 to 10-4. A relative measurement uncertainty of 10-5 is therefore aimed at for the calibration device. The following requirements for the device to be developed can be stated:

- A transportable device is to be developed which should be operated as an adjustable length reference for the calibration of different SMI with a measuring range up to 300mm.
- A diode laser interferometer is to be used for the length measurement. It will allow a small size of the device, which is a prerequisite for the device's transportability. Moreover, such an interferometer will have the necessary accuracy for the calibration of different SMI.
- Traceability can be achieved either using internal reticle markings and other locators, or using external gauge-block material measures. Using such a length reference the diode laser interferometer can be calibrated in regular intervals (daily or prior to each measurement). Since the length measurements are made in air, it is unnecessary to determine the refractive index of air in order to calculate the actual laser wavelength.
- For the design of the basic device and its accessories, it has to be taken into account that internal and external dimensions should be measurable.
The project objectives are in compliance with the work plan of the assistance programme and the priorities set in it because:

- Europe's competitiveness will be improved through an increase in quality resulting from the traceable calibration of the industrial measurement equipment.
- The measurement accuracy in the production environment will be improved by the possibility of on-site-calibrations of measuring instruments.
- The mutual recognition of certificates will be improved by more extensive calibrations.
- Written standards will be influenced by the measuring strategies made possible by the project.
- The more extensive calibration secures the characteristic values of measuring instruments on the basis of written standards.
- The total quality in length measurement with simple measuring instruments will be improved.
- Better quality assurance will also lead to an improved consumer protection through a better control of the production process.

Meccanismo di finanziamento

CSC - Cost-sharing contracts


Bundesrepublik Deutschland
38116 Braunschweig

Partecipanti (4)

Danfoss A/S

6430 Nordborg
Helios Messtechnik Gmbh & Co. KG
74676 Niederhall
1,Pol. Ind. Les Roquetes 1-3
08800 Vilanova I La Geltru
U.F.P. Snc di Panzeri Sergio e C.
Via Iè Maggio
22067 Missaglia