Sunday, 25 December 2016

High Intensity Ultraviolet Light

The 400 watt metal halide bulbs or "super light" can be found in some facilities. This super bright will provide adequate lighting over an area of up to ten times that covered by the 100 watt bulb. Due to their high intensity, excessive light reflecting from the surface of a component is a concern. Moving the light a greater distance from the inspection area will generally reduce this glare. Another type of high intensity light available is the micro - discharge light. This particular light produces up to ten times the amount of UV light conventional lights produce. Reading of up to 60,000 uW/cm2 at 15 inches can be achieved.
Determining whether a magnetic field is of adequate strength and in the proper direction is critical when performing magnetic particle testing. As discussed previously, knowing the direction of the field is important because the field should be as close to perpendicular to the defect as possible and no more than 45degrees from normal. Being able to evaluate the field direction and strength is especially important when inspecting with a multidirectional machine, because when the fields are not balanced property, a vector field will be produced that may not detect some defects.
There is actually no easy -to-apply method that permits an exact measurement of field intensity at a given point with in a material. In order to measure the field strength, it is necessary to intercept the flux lines. This is impossible without cutting into the material and cutting the material would immediately change the field within the part. However, cutting a small slot or hole into the material and measuring the leakage field that crosses the air gap with a Gauss meter is probably the best way to get an estimate of the actual field strength within a part. Nevertheless, there are a number of tools and methods available that are used to determine the presence and direction of the field surrounding a component.