A method for measuring the diameter of a micro liquid drop and the spatial distribution of micro liquid drops by measuring the diameter of an unsharp image due to defocusing and the number of interference fringes thereof is applied to measurement of micro bubbles and applicable even if the spatial distribution density of micro liquid drops or micro bubbles is high. A liquid space where a micro bubble (10) is floating is irradiated with a sheet-like parallel laser beam (2), and a defocus image of the micro bubble (10) to which the laser beam is applied is picked up on a defocus plane (8) through an objective lens (6) in a direction at an angle θ with respect to the direction where the laser beam travels. The interference fringes (9) in the defocus image (10") of the micro bubble (10) are counted, and the diameter of the micro bubble (10) is determined according to formula (4).

L'invention concerne l'étude de la propagation d'un front d'onde de température dans une enceinte contenant un gaz.

Selon l'invention on mesure le temps qui s'écoule entre le passage d'un front (1) d'onde de température, au droit de deux sondes (5) et (6) thermoémissives montées sur la paroi (4) de l'enceinte (3) disposées sensiblement selon un axe (9) de propagation dudit front d'onde, et séparés par une distance (d) connue.

L'invention trouve son application dans les centres d'études et d'essais de machines tournantes et notamment pour l'étude des moteurs thermiques et des carburants qui les alimentent.

A method of measuring the velocities of water volumes flowing co-directionally in separate conduits (14, 18) nested such as in injection or production well-bores allows an oxygen activation measurement of the velocity of the water flow in the tubing-casing annulus (20) in the presence of water flowing in the tubing string in the same direction. The method provides continuous logging at variable or constant cable velocities or stationary logging. Based on the method of velocity gauging, the method isolates the signal from the annular flow and can produce a continuous log of linear and volumetric annular flow rates with depth.

Verfahren zum Ermitteln der Strömungsgeschwindigkeit von Fluiden mittels Laufzeitmessung unter korrelativer Auswertung von in dem Fluid enthaltenen und/oder in es durch einen Sender eingebrachte Wärmeimpulsen. Zur Erhöhung der Meßgenauigkeit erstrecken sich der Sender und der oder die Empfänger bzw. die Empfänger ohne Sender kontinuierlich oder diskontinuierlich über zueinander parallelen Linien, die in Ebenen senkrecht zur Strömungsrichtung der Fluidströmung verlaufen und/oder wird bei Anwendung eines Senders dessen mittlere Pulsfrequenz für die jeweils nächste Messung der Strömungsgeschwindigkeit in Abhängigkeit von der jeweils zuletzt ermittelten Strömungsgeschwindig­keit in vorbestimmter Weise geändert.

A dedicated correlator (10) receives two noise signals (A, B) from spaced sensors sensing noise in a fluid flow. One of the noise signals is delayed (26) by a variable known amount with respect to the other. The amount of correlation between the delayed and undelayed signals is determined by means (32). A sweep voltage generator (40) variably increases or decreases the delay at set rates. A peak lock control means (38) is connected to the sweep generator (40) and to the means (32) for establishing correlation for changing the direction of the sweep generator (40) when it is determined that the amount of correlation is decreasing from a maximum. The particular delay amount corresponding to maximum correlation corresponds, in turn, to the amount of time required of the fluid to travel between the two sensors and, thus, the velocity of the fluid. The particular delay amount varies with variations in fluid velocity since the peak lock control means (38) follows these variations and controls the sweep voltage generator accordingly.

A speed indicating system includes a lamp 20 and lenses 22 and 24 to project a directional light beam 26 across a ship's path 2. An endless slide 28 extends round the lamp 20 and the lens 22. This slide has alternate red and green strips, and the slide part 30 is driven across the beam 26 between the lenses 22 and 24 by variable speed pulse motors.

When a ship is traversing the beam 26, the pilot adjusts the movement of the slide 28 until the flashing of the strips ceases. The pilot then reads out the ship's speed on a calibrated scale.

In another method, the slide 28 is driven through a sequentially repeated stepped speed range. When the ship's pilot sees a fixed light he reads the ship's speed on a visual readout.

L'invention concerne un dispositif pour déterminer la vitesse d'écoulement d'un fluide dans une conduite sensiblement verticale, comprenant deux capteurs sensibles à la même grandeur physique et espacés dans la direction de l'écoulement, la vitesse étant déterminée par corrélation entre les signaux de détection issus des capteurs, lesdits capteurs sont des capteurs de pression différentielle comprenant chacun deux prises de pression espacées dans la direction de l'écoulement, au moins deux prises appartenant à des capteurs différents étant alignées dans cette direction.

Application à la mesure du débit dans un puits producteur de pétrole.