A spherical mercury lamp is a compact, high luminance point light source. When lit and stabilized, it can emit very steady strong light in UV and visible range.
A special box is designed to contain this high pressure bulb to prevent damage to human skin and eyes caused by blowout. A current-limiting resistor in the circuit is used to protect the bulb.
When handling the bulb, please do not touch the glass tube for dirt attached to the tube will affect the output light.
It is widely used in photo-engraving, fluorescence microscopy, direct recording oscillometer, dyeing and printing aging.