Magnetic particle inspection can be performed using particles that are highly visible under white light conditions or particles that are highly visible under ultraviolet light conditions. When an inspection is being performed using the visible color contrast particles, no special lighting is required as long as the area of inspection is well lit. A light intensity of at least 1000 lux (100 fc) is recommended when visible particles are used, but a variety of light sources can be used. When fluorescent particles are used, special ultraviolet light must be used. Fluorescence is defined as the property of emitting radiation as a result of and during exposure to radiation. Particles used in fluorescent magnetic particle inspections are coated with a material that produces light in the visible spectrum when exposed to near-ultraviolet light. This "particle glow" provides high contrast indications on the component anywhere particles collect. Particles that fluoresce yellow-green are most common because this color matches the peak sensitivity of the human eye under dark conditions. However, particles that fluoresce red, blue, yellow, and green colors are available.

The Gould-Bass Magne-Tech® systems feature the most advanced circuitry in the industry providing ease of operation, assured safety for test parts, increased test speeds, and maximum repeatability and dependability of tests. The 3509 models are available in 6000 & 10,000 amperes. They offer FWDC variations with built-in reversing DC push-button demagnetization. Various bench lengths are available. The 3509-01 models offer magnetizing output in both 6000 Amps AC and 6000 Amps FWDC. Demagnetization is both AC and reversing DC. Various bench lengths are available. AC and FWDC magnetizing currents Infinitely variable current control Digital Ammeter with Hold Feature Secondary Solid State Controls Silicon Rectifiers Reversing DC demag on all models AC demag on -01 models Quick Break Feature Standard on All Systems Thermal Overload Protection Current Assurance Indicator Heavy Duty Head/Tailstock Rails Electronic plug-in control modules Maximum ampere output up to 6,000 AC, 10,000 FWDC (see table for details) Unique agitation system maintains bath strength to within 3% of theoretical level Stainless steel tank.