GB/T 5275.2-2022Gas analysis - Preparation of calibration gas mixtures using dynamic methods - Part 2: Piston pumps (English PDF)

1 Scope

GB/T 5275 (all parts) specifies a variety of dynamic methods for preparing mixed gases for calibration. This document is for GB/T 5275

In Part 2, this document specifies the method of continuously generating a mixed gas for calibration using a piston pump. Pistons by means of geometrical measurements

The composition and uncertainty of the prepared calibration mixed gas can be obtained through the calibration of the pump.

From pure gas or mixed gas, a mixed gas for calibration containing two or more components can be prepared by using a gas mixing pump body. The gas mixing pump is composed of at least two piston pumps, and each piston pump has a definite stroke ratio and suitable air intake and mixing devices.

This document applies only to gaseous mixtures or mixtures of fully vaporizable components. When gas components do not react with each other, nor with

When adsorption or reaction occurs on the inner wall of the piston pump, this document is also applicable to the case where corrosive gases are used as raw gas. This document also applies to

When mixed gas is used as raw material gas. At the same time, the preparation of multi-component mixed gas and the multi-step dilution preparation process can be considered as two-component mixed gas.

In the special case of the preparation of the substance, the method specified in this document can also be used for its preparation.

The components of the mixed gas for calibration prepared by the method specified in this document are expressed in the form of volume fraction. Appendix A gives

Data conversion equations for volume fractions and substance volume fractions and related uncertainty assessments.

When adequate quality assurance measures and measurement controls are in place, the relative expansion of the volume fraction of the gas mixture prepared using this method

The development uncertainty can reach the level of no more than 0.5% (coverage factor k=2). Appendix B and Appendix D give the relative expanded uncertainty more

Small calculation examples for some special cases.

Using the method specified in this document, a dilution ratio of 1.10000 can be achieved. Through multi-stage dilution or dilution with mixed gas, it can

Obtain lower volume fraction (can be as low as 1×10-8). The flow range of the final mixed gas can reach 5L/h~500L/h.

2 Normative references

The contents of the following documents constitute the essential provisions of this document through normative references in the text. Among them, dated references

For documents, only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

ISO 7504 Gas Analysis Vocabulary (Gasanalysis-Vocabulary)

Note. GB/T 14850-2020 Gas Analysis Vocabulary (ISO 7504.2015, IDT) positiondata)

Note. Conversion of GB/T 40870-2021 Gas Analysis Mixed Gas Composition Data (ISO 14912.2003, IDT)

ISO /IEC Guide98-3 Uncertainty of measurement - Part 3.Guidelines for expressing uncertainty of measurement [Uncertaintyofmeas-

Note. GB/T 27418-2017 Evaluation and representation of measurement uncertainty (ISO /IEC Guide98-3.2008, MOD)

3 Terms and Definitions

The following terms and definitions apply as defined in ISO /IEC Guide99, ISO /IEC Guide98-3, ISO 14912, ISO 7504 in this document.

GB/T 6052 | GB/T 4844 | GB 4962 | GB/T 5275.7 | GB/T 5275.1 | GB/T 5275.6 | […]