According to different uses, nitrogen products are divided into three types: industrial gaseous nitrogen, pure nitrogen, and high-purity nitrogen.
Industrial gaseous nitrogen is generally used as protective gas, and the technical indicators are in accordance with the provisions of GB3864-83, as shown in the table:
|
Indicator Name |
Indicator |
|||
|
Class I |
Class II |
|||
| Level 1 |
Level 2 |
|||
|
Nitrogen content (volume fraction)/% (not less than) |
99.5 |
99.5 |
98.5 |
|
|
Oxygen content (volume fraction)/% (not greater than) |
0.5 |
0.5 |
1.5 |
|
|
|
Moisture content per bottle of free water/mL (not more than) |
|
100 |
|
|
Dew point/℃ (not greater than) |
-43 |
|
||
Pure nitrogen is used as a replacement gas or protective gas in industries such as chemical, metallurgical, and electronic industries, with technical requirements in accordance with GB8979-88; High purity nitrogen is mainly used in the electronics industry or in the preparation of standard gas mixtures, with technical requirements in accordance with GB8980-88. The specific indicators are shown in the table below:
|
Indicator name |
Pure nitrogen |
High purity nitrogen |
|||
|
Excellent |
Level 1 |
Excellent |
Level 1 |
Level 2 |
|
|
Purity/%(not less than) |
99.996 |
99.99 |
99.9996 |
99.9993 |
99.999 |
|
Oxygen content/10-6(not greater than) |
10 |
50 |
1.0 |
2.0 |
3.0 |
|
Hydrogen content/10-6(not greater than) |
5 |
10 |
0.5 |
1.0 |
1.0 |
|
Carbon monoxide content/10-6(not greater than) |
5 |
5 |
1.0 |
2.0 |
3.0 |
|
Carbon dioxide content/10-6(not greater than) |
5 |
10 |
|||
|
Methane content/10-6(not greater than) |
5 |
5 |
|||
|
Water content/10-6(not greater than) |
5 |
20 |
1.0 |
2.6 |
5.0 |
The purity in the table includes trace amounts of inert gases such as helium, argon, and neon; Liquid nitrogen does not have a specified moisture content.
