The Basic Light has been developed as part of a system for visualizing complex airflows with neutrally-buoyant bubbles. It provides a beam of uniform intensity to illuminate the trajectories of the helium bubbles. The smaller, compact size allows for more flexibility and quicker diagnosis of "large-scale" airflow patterns. Overall, the Basic Light is rugged in design, easy to use and adjust, and relatively cool in operation. The complete assembly with a detachable tripod support weighs only 3.5 lbs. A full-size tripod and storage cases are provided with the light.
This light uses a ELH 300W tungsten-halogen lamp. Lamp life is rated at 35 hours. Power for the lamp and cooling fan is supplied directly through a grounded, plug-in power cord and a toggle "ON-OFF" switch mounted in the bottom cover, along with a general-purpose power entry module. The projection lens and a unique aperture assembly allow focusing of the light beam on any flow from 24" to infinity. Two apertures are included with the Basic Light, an iris and an adjustable slit. The iris provides a circular beam spread that can vary from 2” – 24” in diameter at 6’, while the slit provides a rectangular beam spread from 0” by 22” to 8” by 22” at the same distance.
When on the tripod, the light can be set at any elevation from 0-65”. The tripod pan head allows for 360 degrees of rotation as well as 0 - 90 degrees from horizontal to vertical light orientation.
An adjustable slit and an iris aperture are included with the light. The adjustable slit provides a rectangular beam or "slab" of light varying in width. This is particularly helpful to visualize 2-D airflows or to study 2-D cross sections of a complex 3-D airflow. The iris aperture provides a round beam varying in diameter. This is useful for examination of axisymmetric airflows or the overall examination of any airflow.
To change the width of the slit in the slit aperture, just loosen the four screws that hold the two leaves in place and reset as desired. The orientation of the slit may also be adjusted by the rotation of the aperture in its cradle.
To adjust the beam diameter of the Iris, simply move the iris handle.
Circular Beam Spread: 5 cm – 60 cm Dia @ 180 cm
Iris Diaphragm Diameter: 2.5 mm - 37.0 mm
Rectangular Beam Spread: 1 mm x 56 cm – 20 cm x 56 cm @ 180 cm
Adjustable Slit Width: 0.1 mm – 1.1 cm
Focusing Range: 61 cm - Infinity
Projection Lens Focal Length (Each): 200 mm
Lamp: ELH 300W, 120V
Cooling: Forced Convection
Average Bulb Life: 35 Hrs.
Main Light Dimensions: 10.2 cm H x 10.2 cm W x 34.3 cm L
Overall Height: 16.5 cm
Stand: Ball Head Tripod
Unit Weight: 1.6 kg without the Power Cord or Tripod