During photometric measurements involving the use of photometric lamps it is necessary that the filament of lamp takes a strictly predetermined position with respect to the photodetector and the optical axis of the photometric setup. The errors in positioning of alignment filament with respect to the optical axis of the measuring system lead to increase the uncertainty of measurement ... https://www.roneverhart.com/The-Office-Pop-Vinyl-Figure-Fun-Run-Dwight-1394/