Velocity Sensors

Provide in-vessel agitation (velocity) sensor with alarm... 

Since acceleration is the second derivative of displacement, a piezoelectric accelerometer sensor with an integrator becomes a velocity transducer. This arrangement is gradually superseding the self-generating mo ing-coil velocity sensor (where a coil of wire moves relative to a magnetic field). 

Velocity diagram, axial, 228 Velocity head, 36, 38 Velocity sensors, 352 Velocity transducers, 349 Velocity variation through an axial, 229... 

The capture velocity of a hood is defined as the air velocity created by the hood at the point of contaminant generation. The hood must generate a capture velocity sufficient to overcome opposing air currents and transport the contaminant to the hood. For enclosing hoods, capture velocity is the velocity at the hood opening. In this case, the velocity must be sufficient to keep the contaminant in the hood. In practice, hood shape and the influence of crossdrafts on the measured capture velocity have to be considered. All three velocity components should be measured and used to calculate the magnitude and direction of the total velocity. Other methods used, not as good as the previous one, are to measure the velocity with a directional velocity sensor towards the hood or to measure the net velocity by an omnidirectional velocity sensor. In the last method the main airflow direction should be viewed and evaluated by means of a smoke test (see Sections 10.2.1 and 10.2.2.1). 

Computer numerical control (CNC) means the digital control of machine tool units that consist of series of integrated mechanical actuators, electrical or electrohydraulic servomotors, power amplifiers, position and velocity sensors, and a dedicated computer running under a real-time operating system. 

Known measuring techniques comprise local physical methods (hydrophones, thermoacoustic sensors, aluminum foil erosion, optical sound pressure and velocity sensors, radiation pressure scale, laser-Doppler anemometry), local chemical methods (Weissler reaction, chemiluminescence, electrochemical sensors), global chemical methods (model reactions), and sonoluminiscence (single-bubble sonoluminescence SBSL, multibubble sonoluminescence MBSL). 

Fig. 6.9 Schematic diagrams of enhanced layer velocity sensor. ...

The laboratory shall be equipped with a fume hood. The fume hood should meet any specific safety requirements mandated by the nature of the research program. A discussion of hood design parameters will be found in a later section, but for high hazard use the interior of the hood and the exhaust duct should be chosen for maximum resistance to the reagents used the blower should either be explosion-proof or, as a minimum, have non-sparking fan blades the hood should be equipped with a velocity sensor and alarm should the face velocity fall below a safe limit the interior hghts should be explosion-proof, and all electrical outlets and controls should be external to the unit. It may be desirable to equip the unit with an internal automatic fire suppression system. 

In this section, the operating principles of selected gas velocity sensors and hquid velocity sensors are explained. 

Velocity Sensors, Fig. 1 View of a micromachined sensor structure developed for direction-deptaidtait flow detection. Image taken using a scanning electrrai microscope [2]... 

Ion-Sensitive Field-Effect Transistor (ISFET)-Based Flow Velocity Sensor... 

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