Figure 2-31. Examples of Digital Radiometers.
Guidelines for Measurements.
Some instruments have selectable ranges, and the proper range for the intensity being measured must be used. The
range selector may be changed while under the black light. The sensing element should be at the location and
orientation of the part surface to be inspected. Some instruments have detachable sensors that may be placed directly
on the part surface. White light does not affect the reading of the instrument.
Variables in Black Light Sources.
a. Manufacturing Variations. Black light bulbs are manufactured for other industrial applications. Non-
destructive inspection, NDI, uses only a small portion of the production. The primary users do not