Three Tips to Protect Your BeamSquared Device

Sven Kern, Central European Sales Manager (North)

Before starting the measurements with the Ophir BeamSquared device, it is recommended to perform an “Ultracal™” offset calibration. After the offset calibration, the noise level on the screen shows blueish and greyish signals in balance.

Just lately, the following picture has been taken with an Ophir BeamSquared:

The greyish blur to be seen in the upper two quadrants in figure 2 indicates an Ultracal offset noise. It occurred at auto-stepping and ISO-Auto mode when preparing a training session held with the BeamSquared. This is the first indicator that dust - probably on the variable filters – causes stray light within the BeamSquared measurement system. At that stage it will most likely not influence the measurement itself as the negative pixels shown in light grey are located outside the aperture and will not be used by the UltraCal algorithm anyways. Only with very small beam diameters and a beam position in the upper quadrants the offset noise can lead to differing measurements. Nevertheless, this is one early indicator that there is a contamination in the optical path. Any “noise” to be seen on the picture of the beam, should be considered relevant.

A more prominent hint leading to the conclusion that there is dust on a lens, or a mirror can be seen in figure 3. Small particles lead to these Newton’s rings or bull’s eye interference patterns, they are not to be seen permanently on the screen but only in certain points.

If you suspect a contamination of your optics and want to clean them from dust: Do not use duster spray to clean any optics otherwise condensed gas will contaminate the optics. Externally attached optics should be cleaned as instructed by the respective manufacturer. Generally, the best way is to use optical paper and isopropyl alcohol.

The re-certification procedure of the BeamSquared device includes the cleaning of all optics and mirrors inside the product. Based on a regular use of the BeamSquared, Ophir suggests a re-certification once a year. A re-certification of the BeamSquared system not only reassures you on the performance of your camera, it prevents any issues such as outlined above. The re-certification process will correct bad pixels when possible, clean the imager, and certify that the device is still performing to factory specifications. Any necessary changes, repairs or replacements will be detected upfront and action will be taken after coordination with the customer.