…A simple and flexible way for illuminating helium bubbles!

Basic Light

The Basic Light

The Basic Light projects a beam of uniform intensity to illuminate the trajectories of helium bubbles. A compact design allows for flexibility and a quicker diagnosis of “large-scale” airflow patterns. Overall, the Basic Light is quite rugged and straightforward in design, easy to use, and adjust. The complete assembly with detachable tripod support weighs only 1.6 kg. This support connects to the light’s full-size tripod.  The light elevation is adjustable from 0-165 cm.

The Basic Light uses an ELH 300W tungsten-halogen lamp, with lamp life rated at 35 hours. The projection lens and aperture assembly allow focusing of the light beam on any flow from 60 cm to infinity. Two apertures come with the light, an iris, and an adjustable slit. The iris provides a circular beam spread that can vary from 5-60 cm in diameter at 183 cm, while the slit provides a rectangular beam spread from 0 cm x 56 cm to 20 cm x 56 cm at the same distance.

Component Layout

At the front of the Basic Light, is the projection lens assembly. This assembly is for focusing the light beam. Behind the projection lens is the aperture cradle. The cradle has a thumbscrew, which holds the aperture in place and allows the user to orient the aperture as desired. Toward the center of the light is the lamp housing, which doubles as a heat shield. The lamp housing contains the 300W ELH projection lamp and a thermal fuse to protect it if there loss of airflow through the cooling fan. At the rear of the light is the cooling fan. The fan stays on to cool the lamp as long as there is power going to the light.

Basic Light Layout

Light Apertures

Adjustable slit and an iris apertures come with the Basic Light. The adjustable slit provides a rectangular beam or “slab” of light varying in width, which is particularly helpful to visualize 2-D airflows or to study 2-D cross-sections of a complex airflow. The iris aperture provides a round beam varying in diameter, which is useful for the analysis of axisymmetric airflows or the overall examination of any airflow.

To change the width of the slit, loosen the four screws that hold the two leaves in place and reset as desired. To change the orientation of the slit, rotate it in its cradle.

To adjust the beam diameter of the Iris, move the iris handle.

Light Apertures



basic light


US $1,870

standard nylon case

US $2,165

pelican vault case

Frequently asked questions

We accept payment by Check, Electronic Funds Transfer and Credit Card

Usually, no, because the system is custom-built for you, the customer. Don’t worry; we will go over the use of helium bubbles for the particular application to determine the equipment’s feasibility before any order is placed and accepted. Your success is our success!

Yes, we do. However, payment is due before shipment.

Yes.  Two extra 300W, 120Vac lamps are included.  Additional lamps are in stock and may be purchased for US $38 ea.

Yes.  All systems include a detailed setup and operation manual along with a calibration sheet.

Do you have questions in regards to using helium bubbles for your application? Contact Us