This standard specifies the determination method of trace oxygen in gas, the requirements for instruments, the determination conditions, steps and result processing. This standard is applicable to the determination of trace oxygen in gases such as nitrogen and argon. The determination range is (0.3~10)×10-6(V/V). With the addition of safety measures, this standard is also applicable to the determination of trace oxygen in hydrogen. GB/T 14852-1993 Determination of trace oxygen in gas Yellow phosphorus luminescence method GB/T14852-1993 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of trace oxygen in gases
Yellow phosphorus chemiluminescence method
Determination of trace oxygen in gasesPhosphor chemiluminescence method1 Subject content and scope of application
GB/T 14852--93
This standard specifies the determination method of trace oxygen in gases, the requirements for instruments, the determination conditions, steps and result processing. This standard is applicable to the determination of trace oxygen in gases such as nitrogen and fluorine. The determination range is (0.3～10)×10-6 (V/V). With the addition of safety measures, this standard is also applicable to the determination of trace oxygen in hydrogen. 2 Reference standards
GB/T3723 General safety rules for sampling of industrial chemical products GB/T6680 General rules for sampling of liquid chemical products GB/T6681 General rules for sampling of gaseous chemical products 3 Principle of the method
This method uses the principle of luminescence of yellow phosphorus reacting with oxygen. The photoelectric conversion device is used to convert the luminous intensity into current. Within a certain range, the current and the oxygen concentration have a certain functional relationship, thereby determining the oxygen content in the gas. 4 Instruments
The minimum detection amount of the instrument is 0.3×10-6 (V/V). The schematic diagram of the instrument gas flow is shown below: 1--sample gas; 2-high pressure needle valve; 3-four-way valve; 4-pressure gauge: 5-needle valve, 6-flow meter; 7-solenoid valve; 8-reaction chamber, 9-absorption bottle National Technical Supervision Kitchen 1993-12-30 approved 1994-10-01 implementation
5 Determination conditions
GB/T14852-93
5.1 Sample gas flow rate: 500~700mL/min, the sample gas flow rate is the same as the standard gas flow rate. 5.2 Sample gas pressure: <0.1MPa.
5.3 The operating conditions of the instrument are selected according to the instrument manual and detection sensitivity. 6 Preparation
6.1 Preparation of yellow phosphorus box
Use clean water at about 50'C to melt yellow phosphorus in the empty yellow phosphorus box and fill it up. After cooling and solidification, use a blade to scrape off the oxide on the surface for later use. bzxz.net
6.2 Preparation of instrument
Connect the power supply and gas line joints. The gas line system should be leak-free. Replace the gas line system with sample gas, install the prepared yellow phosphorus box on the instrument, and adjust the flow rate to the specified value. Turn on the power of the instrument, select the operating conditions according to the instrument manual and the requirements of the detection sensitivity, and wait until the instrument works stably.
7 Standard gas
7.1 The standard gas should comply with the provisions of the "Interim Management Measures for National Physical Standards". 7.2 The oxygen concentration in the standard gas should be similar to that in the sample gas to be tested, usually not more than 2 times the oxygen concentration in the sample to be tested, and not less than 0.5 times the oxygen concentration in the sample to be tested. 7.3 The diluent of the standard gas is the same as the sample gas to be measured. The oxygen concentration of the standard gas should correspond to the measuring range of the analytical instrument, which is about 0.8×10~6 (V/V), 4.0×10-6 (V/V), and 8.0×10-(V/V) respectively. One bottle for each. 8 Measurement steps
8.1 Sampling
8.1.1 Safety matters in sampling should comply with the provisions of GB/T3723. 8.1.2 The sampling principles and general provisions of gas samples should comply with the provisions of GB/T6681. 8.1.3 The sampling of compressed gas must use a high-pressure needle valve, and the sample gas should be fully replaced by the method of three times of pressure increase and decrease before being sent to the analytical instrument.
8.1.4 The sampling of liquefied gas should comply with the provisions of Chapter 6 of GB/T6680. 8.1.5 The sampling of gas in the pipeline should use a metal connecting pipe as short as possible to send the sample directly to the analytical instrument. 8.2 Calibration
8.2.1 Use standard gas for calibration. The calibration cycle is .24h. 8.2.2 Send the standard gas in accordance with the provisions of Chapter 7 into the analytical instrument. After fully replacing the gas system, switch the four-way valve to allow the standard gas to enter the reaction chamber until the instrument is stable. Adjust the instrument indication value to the oxygen content value of the standard gas. Repeat the calibration three times. 8.3 Determination
Send the sample into the instrument according to the provisions of Article 8.1. After the injection system is fully replaced, switch the four-way valve to allow the sample gas to enter the reaction chamber. Read the reading after the instrument indication is stable. Repeat the determination twice, and the relative average deviation is not more than 10%. 9 Result expression
Take the arithmetic mean of the two repeated determination results as the determination result. The relative deviation between the single determination value and the average value is not more than 10%. 10 Report
The report should include the following:
GB/T14852—93
All information about the relevant samples. For example, the name, number, sampling point, sampling date and time of the sample, analysis results: oxygen concentration, 10-6 (V/V); b.
Name of the analyst;
Analysis date;
Other operations and instructions not included in this standard. Additional notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of the Southwest Research Institute of Chemical Industry of the Ministry of Chemical Industry. This standard was drafted by the Shanghai Research Institute of Chemical Industry of the Ministry of Chemical Industry. The main drafters of this standard are Jin Peiyun and Dong Duo. 283
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