The microV is a time-of-flight velocity sensor capable of measuring velocity of a fluid at a fixed distance of 0.29″ (7.4 mm)* from the sensor surface within a region approximately 200 by 100 by 300 μm (x by yby z). Two probe versions are available: both measure only 0.35″ (9 mm) in diameter; the standard version is 2.95″ (75 mm) in length and the short version is 1″ (25.4 mm) in length. It has no moving parts, does not include any active components, and is suitable for use in harsh environments. It is still the only sensor of this kind in the industry.
The sensor uses diffractive optic elements to project two parallel light sheets (approximately 300 microns long and 100 microns apart). The light scattered by particles in the flow or by a moving surface is collected through the same sensor element. When a particle moves through the probe volume, it reflects light from the two light sheets, and since their spacing is constant, the time difference between the two received bursts of light correspond to the velocity of the particle. Because the light from each light sheet is received through a different channel, the sensor can measure direction as well as speed.
The microV sensor has an accuracy better than 1% and can measure speeds from nearly 0 to over 100 m/sec.
The microV System consists of a microV probe, driver electronics, and the BP-microV Burst Processor acquisition hardware and processing software. Optionally available is a precision electronic linear traverse (controlled from within BP-microV software) and a computer with the hardware and software installed and verified by MSE technicians.
Both the light source and the receiver are connected to the sensor via optical fibers, so the electronics can be safely stowed several meters from the probe. (Steel-jacketed optical conduits are available for industrial applications.)
Feel free to contact us about custom solutions implementing the microV System.
*These distances are measured in air. When aimed into an experimental vessel with a different fluid, the probe volume will be farther from the probe and it will be slightly larger. Please refer to the specifications at left for examples.
The microV probe is protected under U.S. Patent No. 6,956,230.