Measuring unit to assess and control screen exposure times
The KIWO-UV-METER PRO has two integrated measurement possibilities: - It indicates by how much the exposure time for different light sources and distances must be increased or decreased to achieve an even copying result (factor measurement). - It measures the power of the most suitable UV-light in mW/ cm2 for the exposure of Diazo and SQB sensitized photoemulsions and stencil films. The KIWO-UV-METER PRO has been calibrated by KIWO for a 5.000 W metal halide lamp at a distance of 1 meter to give an exposure factor of 1,0. Taking the exposure time quoted in the technical information sheet for the respective photoemulsion and the coating technique employed, no matter what type of light source is used, it is possible to determine the exposure time required by multiplying the quoted exposure time by the exposure factor measured. If the measuring mode is changed to mW/ cm2, the energy coming onto the emulsion can be determined. The measuring head of the KIWO-UV-METER PRO has a filter which only absorbs the UV-light in the range of 320 - 420 nm which is necessary for the exposure of photoemulsions. This largely prevents measuring errors caused by a spectral shift of the light intensity due to the age of the lamp. The measuring result no longer depends on the type of light source as the filter absorbs the greater parts of the visible light and the short-wave UV-light as well. It is therefore not important if a HPR-lamp, actinic fluorescent tubes, metal halide lamps or any other light source is measured. The measuring results determined by using the KIWO-UV-METER PRO are comparable with each other.