Laser PIV System

Laser:

• Solid-state air-cooled 200 mW, 660 nm laser diode (Class 3b).
• Standard optics produce a c. 3 mm thick, 45° light sheet (c. 200 mm wide at 250 mm).
• Interchangeable 22° light sheet optic available (item H41-3).
• Pulse separation (?t) of between 100 µs - 5 s (in steps of 10 µs).
• Pulse width of between 10 µs - 32 ms (in steps of 10 µs).

Camera:

• Super-sensitive VGA CMOS sensor: 640 * 480,

-6.0 µm pixels (1/3" format); -~50% quantum efficiency at 660 nm; -75 - 110 dB dynamic range; -4.8 V/lux·sec sensitivity.

• Trigger input enables image pair acquisition to be synchronised with external events.
• Accepts standard CS- or C-mount lenses (12.5mm f/1.4 lens supplied).
• Camera exposure can be linked to the laser's pulsing, thereby enabling operation in a lit room.

Software Processing:

• Data refresh and recording rate up to 16Hz (dependent on the computer speed, the selected acquisition and PIV analysis parameters and the recording taking place)
• Real-time, or offline, 2-component vector calculation.
• Single pass or adaptive multi-pass cross-correlation with 8, 12, 16, 24, 32 or 64 pixel window sizes.
• 0% or 50% window overlap (i.e. maps of up to 19,000 vectors).
• Optional vector interpolation and filtering based on:

User-supplied velocity limits; RMS of neighbouring vectors' values.

• Calculation of the following derived scalars:

- Vector angle and magnitude; - Vorticity and swirl; - Time-averaged mean velocity; - RMS and turbulence intensity. - Where applicable, vector component and statistical sample number are user-defined.