| 摘要 |
A laser Doppler anemometer having two laser diodes (LD1, LD2) whose laser beams (1, 2) are concentrated in a specific region of a flow (3), containing particles, of a fluid in such a way that a virtual interference fringe pattern is produced in this region, and having at least one photodetector (D1) for detecting light scattered by the flowing fluid. The wavelength of the laser diodes (LD1, LD2) is set and stabilised by a temperature and current control (12, 13). The laser Doppler anemometer permits investigation of the sign (the direction) of flows (3) if the two laser diodes (LD1, LD2) are set to different emission wavelengths, and there is present a control circuit (8, 9, 10) for keeping the differential frequency constant which acts on the temperature and/or current control (13) of at least one of the laser diodes (LD1, LD2). <IMAGE>
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| 申请人 |
BUNDESREPUBLIK DEUTSCHLAND, VERTRETEN DURCH DEN BUNDESMINISTER FUER WIRTSCHAFT, DIESER VERTRETEN DURCH DEN PRAESIDENTEN DER PHYSIKALISCH-TECHNISCHEN BUNDESANSTALT, 3300 BRAUNSCHWEIG, DE |
发明人 |
DOPHEIDE, DIETRICH, DR.;FABER, MICHAEL, DIPL.-ING. DIPL.-PHYS.;TAUX, GUENTER, DIPL.-PHYS., 3300 BRAUNSCHWEIG, DE;REIM, GERHARD, DIPL.-ING., 3301 ROTHEMUEHLE, DE |
