GB 10627-89 Preparation of Standard Gaseous Mixtures by Static Volumetric Method
This standard specifies a static volumetric method for the preparation of standard gaseous mixtures for the chemical analysis of gases. This method is mainly applicable to gaseous components which are miscible in their gaseous state and not chemically reactive.
The standard gaseous mixtures prepared by the method described in this standard are either of fixed compositions or of variable compositions. The fixed composition of the standard gaseous mixtures is presented as the accepted concentration or partial pressure of the constituents in the analytical system. The ranges and the accuracy of the fixed composition of these gaseous mixtures conform to the requirements in this standard.
When preparing standard gaseous mixtures with variable compositions, the proportion of each constituent may be varied over wide ranges. The accuracy required depends on the purpose of their use and mainly depends on the skill and experience of the operator.
The standards described in this standard are suitable for use in connection with analytical instruments.
1. Scope
This standard specifies a static volumetric method for the preparation of standard gaseous mixtures for the chemical analysis of gases.
2. Normative references
The following documents are essential for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB/T 26639-2011, Static volumetric analysis
3. Terms and definitions
The terms and definitions defined in GB/T 26639-2011 are applied to this document.
4. Preparation of standard volumetric mixtures by static volumetric method
4.1 Basic conditions of preparation
4.1.1 The pressure of the working environment should be close to the atmospheric pressure.
4.1.2 The temperature of the gaseous mixtures should be close to normal atmospheric temperature (25°C).
4.1.3 The relative humidity of the gaseous mixtures should be close to normal atmospheric humidity (20-50%).
4.2 Preparation of a gaseous mixture with fixed composition
Prepare a gaseous mixture with fixed composition by static volumetric method in accordance with the requirements of GB/T 26639-2011.
4.3 Preparation of a gaseous mixture with variable composition
For the preparation of a gaseous mixture with variable composition, prepare standard gaseous mixtures with fixed composition first, then vary the proportions of the components in the gaseous mixtures according to the requirements of the measuring design and the sample matrices.
5. Inspection
The accuracy of the standard gaseous mixtures prepared by static volumetric method shall meet the requirements in Table 1.
Table 1 Accuracy requirements for static volumetric preparation of gaseous mixtures
6. General requirements
In the preparation of standard gaseous mixtures, the operator should strictly adhere to the calculations based on the actual conditions. If necessary, standard gravimetric method is used for reference.
7. Packaging and storage
7.1 The standard gaseous mixtures prepared by static volumetric method should be transferred and stored in cylinders or other hermetically sealed containers as soon as possible. The sealed container should be labeled with the name, content and storage date of the gaseous mixtures.
7.2 The standard gaseous mixtures prepared by static volumetric method should be stored in a clean, dry, cool and well-ventilated indoor environment.
7.3 Store the standard gaseous mixtures separately from other reagents to prevent contamination and dilution.
