We have been using Air Liquide Instrument Grade Air for venting the 40m vacuum envelope. It is no longer available.
The replacement is Alphagas 1, total hydrocarbon <0.1% ppm
LINK TO Alphagaz
Air Liquide > ALPHAGAZ™ Specifications
   
ALPHAGAZ™ Specifications
ALPHAGAZ™ range of Pure Gases for Analysis: two purity levels tailored to cover all your analytical needs.
Because each analytical application is sensitive to critical impurities that can affect your results, tests in our research center and analyzer manufacturers' studies confirm that the main impurities are moisture, oxygen and hydrocarbons.
Based on these critical impurities, Air Liquide has developed ALPHAGAZ™ brand with a Maximum Impurity Level (H2O, O2, CnHm).
- The Maximum Impurity Level is the same across the whole product range. This constitutes a guarantee of quality with regard to major critical impurities and contamination tracers. ALPHAGAZ™ 2 offers an even greater guarantee in terms of purity (CO, CO2, H2).
- The Minimum Total Purity is a prerequisite for product quality, but we do not stop there: Air Liquide selects and controls its gas sources by defining specifications regarding impurities that are critical for your analysis or application.
| ALPHAGAZ™ 1 |
ALPHAGAZ™ 1 |
ALPHAGAZ™ 2 |
ALPHAGAZ™ 2 |
ALPHAGAZ™ AUTO IV |
ALPHAGAZ™ CO2 SFC |
He, N2, H2,
Ar, O2 |
Air |
He, N2, H2,
Ar, O2 |
Air |
Air*, N2, O2 |
CO2 |
| Specifications (ppm vol): |
H2O < 3 ppm
O2 < 2 ppm
CnHm < 0.5 ppm |
H2O< 3 ppm
CnHm< 0.1 ppm
CO2 < 1 ppm
CO < 1 ppm |
H2O < 0.5 ppm
O2 < 0.1 ppm
CO2 < 0.1 ppm
CO < 0.1 ppm
CnHm < 0.1 ppm
H2 < 0.1 ppm |
H2O < 0,5 ppm
CnHm < 50 ppb
CO2 < 0,1 ppm
CO < 0,1 ppm
NOx < 10 ppb *
SO2 < 10 ppb* |
CnHm < 0.2 ppm
CO2 < 0.5 ppm
CO < 0.5 ppm
NO/NOx < 0.1 ppm |
H2O < 5 ppm
O2 < 2 ppm
CnHm < 2 ppm
NVOC* < 2 ppm
CO < 5 ppm
NO + NO2 < 2 ppm
S Total < 1 ppm
H2 < 0.5 ppm |
| |
20 ± 1 % O2 (Europe)
21 ± 1% O2 (North America) |
|
20,9 ± 1 % O2
*: Detection limit |
*20 ± 1 % O2 |
*NVOC: Non Volatile Organic Compounds |
| Minimum Total Purity |
|