Standard No.:	GB/T 17623-2026
English Name:	Determination of componental contents of gases dissolved in insulating oil by gas chromatography method
Chinese Name:	绝缘油中溶解气体组分含量的气相色谱测定法
Professional Classification:	GB    National Standard
Source Content Issued by:	SAMR, SAC
Issued on:	2026-04-30
Implemented on:	2026-8-1
Status:	to be valid
Superseding:	GB/T 17623-2017 Determination of componental contents of gases dissolvedin insulating oil by gas chromatography method
Target Language:	English
File Format:	PDF
Word Count:	17000 words
Translation Price(USD):	510.0
Delivery:	via email in 1~5 business day

GB/T 17623-2026 Determination of componental contents of gases dissolved in insulating oil by gas chromatography method English, Anglais, Englisch, Inglés, えいご This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered. ICS CCS National Standard of the People's Republic of China ‌GB/T 17623-2026 Determination of componental contents of gases dissolved in insulating oil by gas chromatography method 绝缘油中溶解气体组分含量的气相色谱测定法 Issue date: 2026-03-31 Implementation date: 2026-10-01 Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China the Standardization Administration of the People's Republic of China Contents Foreword 1 Scope 2 Normative References 3 Terms and Definitions 4 Method Summary 5 Sample Collection and Storage 6 Materials 7 Instruments and Equipment 8 Preparation 9 Test Procedure 10 Minimum Detectable Concentration 11 Precision 12 Accuracy 13 Report Annex A (Informative) Common Gas Circuit Configurations and Chromatographic Columns for Gas Chromatographs Annex B (Informative) Method for Determining the Recovery Rate of Dissolved Gases in Insulating Oil Annex C (Informative) Principle of Gas Extraction Annex D (Informative) Calibration and Analysis Method Using an Automatic Sampling Vacuum Gas Extraction Device Annex E (Informative) Method for Determining the Gas Partition Coefficient of Insulating Oil Annex F (Informative) Gas Partition Coefficients of Imported Mineral Insulating Oil Annex G (Informative) Secondary Dissolution Equilibrium Method Bibliography Determination of dissolved gas components in insulating oil by gas chromatography method 1 Scope This document describes the method for determining the content of dissolved gas components (including hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, carbon dioxide, oxygen and nitrogen, etc.) in insulating oil by gas chromatography. This document applies to the determination of dissolved gas component content in insulating oil (mineral oil, natural ester, synthetic ester, etc.) used in oilfilled electrical equipment. The determination of free gas (gas in gas relays, gas above the oil surface in equipment, etc.) in oilfilled electrical equipment shall refer to the relevant content in 9.2 and 9.3.3. 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 (including any amendments) applies. GB/T 7597 Method of sampling for electric power oil (transformer oil and turbine oil) DL/T 722 Guide for the analysis and judgment of dissolved gases in transformer oil DL/T 2217 Guide for dissolved gas analysis in natural ester and synthetic ester oils for transformers 3 Terms and Definitions No terms and definitions are defined in this document. 4 Method Summary A certain volume of oil sample is subjected to headspace gas extraction or vacuum degassing to obtain the dissolved gases in the sample. The gas components are separated, detected and calculated using a gas chromatograph to obtain the content of dissolved gas components in the oil. The determination result for the content of dissolved gas components in the oil is expressed in microlitres of each gas component per litre of oil (μL/L) at a temperature of 20 °C and a pressure of 101.3 kPa. 5 Sample Collection and Storage 5.1 The collection of oil samples from oilfilled electrical equipment shall be carried out in accordance with the provisions of GB/T 7597. 5.2 The collection of free gas samples from oilfilled electrical equipment shall be carried out in accordance with the provisions of DL/T 722. 5.3 Samples shall be protected from dust, vibration, light and moisture during transport and storage. 5.4 Oil samples should be analysed within 4 days after sampling. Gas samples should be analysed as soon as possible after sampling. 6 Materials 6.1 Nitrogen (or argon): purity not less than 99.99 %. 6.2 Hydrogen: purity not less than 99.99 %. 6.3 Helium: purity not less than 99.999 %. 6.4 Air: dry and oilfree. 7 Instruments and Equipment 7.1 Oilgas separation device 7.1.1 Constant temperature and timing oscillator Reciprocating oscillation frequency: 275 times/min ± 5 times/min; amplitude: 35 mm ± 3 mm; temperature control accuracy: ±0.3 °C; timing accuracy: ±2 min; equipped with a fixing clip to hold 100 mL glass syringes. 7.1.2 Vacuum degassing device Degassing efficiency shall not be less than 90 %, and the annual average change in degassing efficiency shall not be greater than 5 %. 7.1.3 Automatic headspace sampler It shall have the functions of mechanical oscillation, temperature control, pressure regulation and automatic quantitative sample injection, and shall allow each dissolved gas component to reach equilibrium between the two phases within a certain period of time. NOTE: One of the above oilgas separation devices may be used for testing. 7.2 Gas chromatograph It shall include a gas circuit system, injection system, temperature control system, chromatographic column, detector, and recording and data processing device. The detector shall be equipped with a thermal conductivity detector (for measuring hydrogen, oxygen and nitrogen), a flame ionisation detector (for measuring hydrocarbons, carbon monoxide and carbon dioxide), a nickel catalyst converter (for converting carbon monoxide and carbon dioxide into methane), or a helium ionisation detector. The reaction temperature of the nickel catalyst converter in the gas circuit system should be 350 °C to 360 °C. The resolution of the chromatographic column for adjacent detected components shall meet the quantitative analysis requirements. The detection sensitivity of the gas chromatograph shall meet the minimum detectable concentration requirements for each component in the oil specified in this document. Common gas circuit configurations and chromatographic columns for gas chromatographs are given in Annex A. 7.3 Stainless steel injection needles Dental No. 5 needle: length 40 mm. 18G No. 1 needle. 7.4 Doubleended needle (for mechanical oscillation method) A schematic diagram of the doubleended needle is shown in Figure 1. It can be made from a dental No. 5 needle. 7.5 Glass syringes Glass syringes with capacities of 100 mL, 5 mL and 1 mL. They shall be airtight, with plungers that move smoothly without sticking. 7.6 Rubber sealing caps for syringes They shall match the taper of the glass syringes (7.5), have good elasticity and be airtight. 7.7 Headspace vials A schematic diagram of an automatic headspace vial is shown in Figure 2. Capacity: 20 mL. Equipped with a perforated aluminium cap and a PTFE septum. 7.8 Crimping tool It shall be compatible with the headspace vials. 7.9 Standard gas mixture National certified reference materials shall be used. The components of the standard gas mixture shall be consistent with the components to be detected. Typical concentration ranges are given in Table 1. 8 Preparation 8.1 Airtightness check of glass syringes Use a glass syringe to take an oil sample containing a detectable amount of hydrogen. Store it for at least two weeks. Analyse the hydrogen content of the sample at the beginning and end of the storage period. When the weekly hydrogen loss is less than 2.5 %, the glass syringe is considered airtight. 8.2 Calibration of glass syringe graduation At room temperature, use the gravimetric method to calibrate the 40.0 mL graduation of a 100 mL glass syringe and mark the position. 8.3 Calibration of headspace vial graduation At room temperature, use the gravimetric method to calibrate the 15.0 mL graduation of a headspace vial and mark the position, and also calibrate the full mark. 8.4 Degassing device 8.4.1 Constant temperature and timing oscillator Set the control temperature and time of the constant temperature and timing oscillator. Heat it to 50 °C and keep it on standby. 8.4.2 Vacuum degassing device Measure the degassing rate of the vacuum degassing device once a month. The detection method is given in Annex B.