| Different applications call for different levels of gas purity. Purity is expressed as a percentage value, for example 99.996%. This is also abbreviated to 4.6, where the first digit refers to the number of 9s and the last digit indicates the finest purity gradation.
Impurities in laser gases, for example, impede laser performance by lowering the output power and disturbing the uniformity of the electrical discharge. They also result in frequent service and maintenance intervals for the laser optics. The most harmful impurities have been identified as water vapor and hydrocarbons.
Laser gas impurities can be traced to the gas cylinders themselves. However, they can also result from a poorly designed gas distribution system. The regulators, for example, must be designed to support the purity levels required. The hose material must also be carefully selected. Numerous materials do not provide resistance against permeation and impurities from the ambient atmosphere may enter the hose through the walls and dilute the high-purity gases within. To ensure reliable, consistently high quality, high purity supply systems must be carefully selected and professionally installed. |
