气体浓度的表示方法

气体浓度的表示方法

气体浓度的表示方法：



1，体积比表示法：即一定体积气样中所含被测气体物质所占的体积百分数（%）。在微量分析中通常以ppm表示， 1% = 10000ppm

2，重量、体积比表示方法：即每立方米气样中所含被测气体物质的毫克数（毫克/立方米 mg/m3 ）。

两种浓度之间的换算

（以H2S为例）在标准状况下，即大气压为760mmHg ，温度为0℃时：

1ppm = M/22.4mg/m3（1）
由（1）式可 推导如下：
1mg/m3 = 22.4m M/ppm （2）
M ---- 被测物质的分子量
将M（H2S） = 34.08分别代入上式（1）和（2）中，则：
1 ppm = 34.08 ÷ 22.4 = 1.52 mg/m3
1 mg/m3 = 22.4 ÷ 34.08 = 0.66 ppm

我们通常换算为实验室温度（20℃），（0℃～20℃）之间温度对体积影响的换算系数为0.9316，则得：
1 ppm = 1.52 mg/m3 × 0.9316 = 1.42 mg/m3
1 mg/m3 = 0.66 ppm ÷ 0.9316 = 0.71 ppm

The Single Clove Garlic (also called Solo Garlic) is produced in the high mountain area of Yunnan Province in China, it is grown with organic fertilizers without chemical pollution. The harvest time is February to March each year. Solo garlic's price is higher than regular multi-clove garlic.

1. Commodity name: Single clove garlic

2. Feature: purple and white in color, good-looking appearance, unique flavour, strong fragrant taste compared with regular multi-clove garlic.

3. Origin: Yunnan province of China
4. Size: 2.5-3.0cm, 3.0-3.5cm, 3.5cm and up
5. Packing:
a) prepack: 250g/bag or basket, 10kgs/carton;
b) Loose packing: 10kgs/carton, 10kgs/mesh bag
c) packed according to clients` requirements.
6. Supply period: all the year round
a) Fresh season: early March to July
b) Cold storaged season: early August to the next February
7. Transporting and storing temperature: -3°C--+2°C
8. Shelf life: stored for up to 12 months in the proper conditions

Solo Garlic

Solo Garlic

Solo Garlic

Solo Garlic

Solo Garlic,Fresh Solo Garlic,White Solo Garlic,Natural Solo Garlic

JINING FORICH FRUITS & VEGETABLES CO., LTD. , https://www.forichgarlic.com