T/CMA YJ044-2020 in English

本标准规定了天然气热值声光测量仪(以下简称热值仪)的术语、定义、工作条件、技术要求、试验方法、附加内容、检验规则、包装、标识、贮存、运输等方面的要求。
本标准适用于测量甲烷为主要成分的链烷烃气体和氢气的热值，其中氮气、氧气、二氧化碳、一氧化碳等其他杂质气体体积含量之和不超过20%。

Scope

This standard stipulates the requirements for terms, definitions, working conditions, technical specifications, testing methods, additional content, inspection rules, packaging, labeling, storage, and transportation of natural gas calorific value photometric measurement instruments (hereinafter referred to as calorimeters).

(I) Scope
This standard applies to the calorific value measurements of methane-dominated alkanes and hydrogen gases. The combined volume content of nitrogen, oxygen, carbon dioxide, carbon monoxide, and other impurity gases should not exceed 20%.

(II) Normative References
The normative references cited in this document form an essential part of it. For dated references, only the specified version is applicable to this document; for undated references, their latest versions (including all amendments) are applicable.

(III) Terms and Definitions
Mainly defines natural gas calorific value photometric measurement instrument, calorific value, calorimetric determination, standard gas, and measurement error.

(IV) Working Conditions
The measurement range, working pressure, and temperature range were quantitatively specified. The calorific values obtained under these conditions are credible; if the measurements exceed this working range, all parameters of the calorimeter need to be recalibrated to ensure the authenticity of the data.

(V) Technical Requirements and Experimental Methods
This group standard mainly puts forward requirements on various aspects such as product functions, information processing capabilities, and interference resistance. It also specifies physical characteristics of the product itself. According to technical requirements, targeted experimental methods were designed, with experiments based primarily on national standards or technical regulations. The scientific nature, operability, and reproducibility of the experimental methods have been verified. Examinations are divided into mandatory inspection items, sampling inspections, and detection projects for optional functions.

(VI) Additional Content
Each calorimeter should come with a performance specification description upon delivery, including at least content from Appendix B or similar information. To accommodate product applicability, performance indicators can be adjusted; however, all specific indicators in Appendix B must be explicitly mentioned.

(VII) Inspection Rules
For the product to meet national regulations before going on the market, it should undergo type testing under any of these circumstances: a calorimeter must pass inspection by the manufacturer's quality control department and have a product qualification certificate. The following inspections are required:

Item No. Inspection Item Type Test Factory Test Technical Requirements Article Number Testing Method Article Number
1 Measurement Error √ √ - 5.1.1 6.2.1
2 Adaptability √ - √ 5.1.2 6.2.2
3 Repeatability √ - √ 5.1.3 6.2.3
4 Flow Characteristics √ √ - 5.1.4 6.2.4
5 Response Time √ √ - 5.1.5 6.2.5
6 Sudden Temperature Changes √ - √ 5.1.6 6.2.6
7 Humidity - - - 5.1.7 6.2.7
8 Storage Temperature - - - 5.1.8 6.2.8
9 Shell Protection Level - - - 5.2.1 6.3.1
10 Sealing Performance √ √ - 5.2.2 6.3.2
11 Salt Spray Resistance √ - - 5.2.3 6.3.3
12 Solar Radiation - - - 5.2.4 6.3.4
13 Flammability of External Surface - - - 5.2.5 6.3.5
14 Explosion-proof Performance √ - - 5.3 6.4
15 Remote Device √ √ - 5.4 6.5
16 Display Information - √ - 5.5 6.6
17 Power Supply ▲ ▲ - 5.6 6.7
18 Electromagnetic Compatibility √ - - 5.7 6.8
19 Appearance √ √ - 5.8 6.9

Note 1: √ indicates a mandatory inspection item, √- indicates a sampling inspection item, ▲- indicates a mandatory inspection item for optional functions or characteristics, and △- indicates a sampling inspection item for optional functions or characteristics.

(VIII) Packaging, Labeling, Storage, Transportation
At various stages before delivery, quality issues may arise. This section provides reference suggestions for related problems.

(IX) Appendices
This standard includes three informative appendices: Appendix A details a typical calorimeter product structure; Appendix B explains the performance indicators of the calorimeter; and Appendix C describes the detection principles and methods of the calorimeter. These contents serve as effective supplements to the calorimeter product, provided for reference.