Technical Documentation
NOX, SOX measures
The measurement method for the gas components removed by the air washer is introduced below.
Related data to air washer
Air washers remove trace amounts of water-soluble gaseous contaminants from outside air.
We will introduce the analysis method for trace amounts of contaminants and the water quality management method for airwasher cleaning water.
Gas Analysis Method
Trace gas analysis in air
Washing Water
Indicators used for managing the quality of circulating water in air washers
| Volume resistivity (specific resistance) ※The inverse is called "conductivity" and its unit is S (Siemens)/m |
Tap water: 5Ω・cm (measured at SINKO technical R&D) For semiconductor manufacturing processes：＞18.2MΩ・cm
The higher the value, the higher the level of purity of the water, and ultrapure water does not conduct electricity. |
|---|---|
| pH (hydrogen ion concentration) | Decreases when acidic gases such as SOX are dissolved in the cleaning water |
General evaluation items for the quality of ultrapure water
| Volume resistivity （specific resistance） | ＞18.2MΩ・cm |
|---|---|
| Particles | ＜0.2 / I |
| Viable bacteria count | ＜1 / I (Bacteria) |
| TOC (total organic carbon) | ＜ 1ppb Indicators for organic matter in water |
| Dissolved oxygen | ＜ 1ppb |
| Silica | 0.5ppb Si02 Oxides of silicon |
| Metal ions | ＜ 20ppt |
Dissolution of chemical gases in water
Dissolving ammonia in water
Ammonia dissolves in water and exists as ammonia ions and hydroxide ions in water.
Dissolution of sulfur dioxide in water
Sulfur dioxide (SO2) dissolves in water and exists in the water as sulfite ions and sulfate ions.
