This standard specifies the film-covered galvanic cell electrochemical method and electrolytic electrochemical method for the determination of trace oxygen in gaseous ethylene or propylene. This standard is applicable to the determination of industrial ethylene and propylene with a content of not less than 1Ml/m GB/T 3396-2002 Electrochemical method for the determination of trace oxygen in industrial ethylene and propylene GB/T3396-2002 Standard download decompression password: www.bzxz.net

ICs 71. 080, 01
National Standard of the People's Republic of China
CB/T3396—2002
Ethylene and propylene for industrial use-Determination of trace oxygen-Electrochenical method
2002 - 10 - 15 Issued by
People's Republic of China
National Quality Supervision, Inspection and Quarantine Administration
2003-04-01Implementation
GR3396-7C67
The winning bid is a continuation of the original standard (5/T339-1) for the determination of the content of trace oxygen in the sieve of ethylene and propylene. The main revisions to the original standard are: Based on the standard of ordinary Beijing battery electrochemical method and electrolytic electrochemical removal film
This standard shall be effective from the month of implementation: At the same time, it shall replace GB/T339-1 31S2. This standard was proposed by China Petrochemical Corporation and drafted by the National Chemical Standards Committee of China Petrochemical Corporation. This standard was drafted by China Petrochemical Corporation and Shanghai Wuhui Chemical Research Institute. The drafters of this standard are: Youxian Guang, Chuan, Ke Houjun, Ding Daxi. The standard was first issued in December 198? 1 Scope
National Standard of the People's Republic of China
Ethyleae and propylene for industrial useDetermination of trace oxygenElecirochemical method
GR/T 3396 ---2002
B:T339512
This standard specifies the determination of trace oxygen in gaseous ethylene or olefins by membrane-mounted electrochemical method and electrolytic electrochemical method. This standard is applicable to the determination of industrial ethylene, propylene oxide with a content of not less than 1m, plate-type molecular oxygen. 2 Reference standards
The texts contained in the following standards constitute the provisions of this standard through the addition of this standard. When this standard is revised, the versions shown are all valid. All standards will be revised. For convenience, all parties to this standard should use the latest versions of the following standards: H/16682-195 6 Specifications and or test methods for analytical laboratory water (nen1S () 31917281 Industrial state sampling (e8073821956
13290-1551 Industrial and 1 Screening and extraction method (S856315873 Method Summary
3-1 Membrane performance center chemical method
When the gas reaches a certain rate of flow through the measuring cell equipped with the required cover electrode (fuel cell), the gas user oxygen molecules diffuse through the surface of the electrode and the turbulent compound is corrected, and the cathode made of the gold film reacts, and the external circuit obtains electricity, +2H.0 +4~→40OH
At the same time, the KH in the anode aqueous electrolyte corrodes and reacts to produce an external auxiliary ion 20HPb +PI+H,0+2
The total reaction rate of the bed pool is:
2Hh 10, ----2b0
The magnitude of the current generated by the external electrolysis is proportional to the external positive charge in the gas. At the total pressure test, the current becomes proportional to the concentration in the gas
3-2 Chemical method
When the gas is electrolyzed at a certain rate, the gas molecules expand in the electrolyte cell filled with potassium hydroxide. Under the influence of the current, the oxygen molecules come to the platinum and gold to be reduced at the cathode made of gold. The molecules outside the circuit are given electrons: 0, +211, 0+: +01
When the pressure is reduced, the II- in the front positive surface is oxidized and the electrons are released to the external circuit: +
Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on 2002-10-15, 2003-04-01 Implementation
GBT3396
Original material does not need to be supported, and the oxygen generated is gradually released through the porous material near the camera. The size of the core is proportional to the increase in the absorption rate and the material
4.1 Commonly used laboratory instruments;
4.2 Oxygen measurement
4.2.1 Typical questions cover the original battery: the total end of the battery is used to measure the oxygen. The reading meter and other parts are shown in the figure. The detection limit of the instrument is 1mI. The structure of the original cell is shown in the figure: The electrodes of the original battery are made of gold, silver, platinum, or zinc. The original cell is equipped with a receiving electrode to keep it moist. 4.2.2 Electrochemical measurement method: The electrolytic cell, micrometer and other parts form the core diagram of the transmitter, see Figure 2. 1 Schematic diagram of a typical primary cell. Electrolytic source oxygen flow diagram. Sample gas is introduced into the air, etc. |The same gas from the mouth
4.3 frequency plate: 0.1L/mir~2/mn
GR/T3396-2DC2
4.4 screw bottle stainless steel capillary: inner diameter 1m~2mm, length 2m-4:4.5 humidifier, the device is equipped with a plastic price, on which there is a rubber hose with a length of 1 benefit, inner diameter 11m, outer diameter mm, see Figure 5. When assembling the humidifier, first purge the silicone tube and 4.6 Water bath, control the temperature to 5UC
4.7 Hot water, pass 66% first-class water through the gasket before use to remove the gas. 4.8 High-purity nitrogen volume fraction is not less than 95.%, and the oxygen content is less than 5ml/r4.9 Standard energy gas: known gas (such as sensitive gas, oxygen, etc.) | Figure booster
5 Sampling
GB13289 GB/13290 installation requirements for winter sampling, 6 special steps
6.1 Instrument connection (see
6.1.1 Measuring device drug pipeline connection
Device water distribution
To prevent the atmosphere from penetrating into the gas path, all connecting pipes and follow-up parts are made of stainless steel: at the port of the stop device, step CB/I 3396-2002
Connect a stainless steel capillary with a length of 50cm and an inner diameter of 1m-2mm to prevent the back diffusion of hydrogen in the air and introduce a certain amount of oxygen. 6.1.2 Adjustment of gaseous samples
Use a stainless steel pipe to connect the oxygen measuring instrument and the sample or sampling line. If necessary, a gold four-diaphragm pressure reducing valve can be used to adjust the positive pressure of the sample gas. 6.1.3 Cooling and gasification of liquid samples
When measuring liquid samples, measures should be taken to completely gasify the sample into a continuous gaseous sample and airflow. The sample can be introduced into a 30~-5cm water bath. The end of the stainless steel capillary (4.4) is rotated to ensure that the liquid sample is fully evaporated and gasified: record the collected data
Assembly diagram of oxygen measuring instrument
6.2 Connection diagram Before the formal measurement, check whether the pipes and joints are in good condition, maintain the normal gas flow, observe the reading of the oxygen meter after the measurement, and then increase the gas flow by one time. The reading of the oxygen meter should show no obvious change. The user should follow the instructions.
6.3 Calibration
According to the instrument instructions, calibrate the instrument with the atmosphere or the standard gas of oxygen content. The flow should be consistent with the gas used for the measurement sample. The calibration is generally performed once every hour or so. 6.4 Sample preparation
Connect as described in subsection 1, prepare the instrument parameters and adjustment parameters according to the instrument instructions, and introduce the gaseous sample with the specified flow. After the instrument indication stabilizes, the time is less than 10 minutes, and all the values ​​are recorded! To ensure the good working condition of the analyzer, high-temperature nitrogen can be used to flush the test sample at a relatively high flow rate before the end of the test. For the membrane cell method, the point air flow humidified by the filter can be passed through the measuring cell at a flow rate of 11/-2L/h to maintain the good working condition of the cell.
Representation of results
1. Read the reading indicated on the meter of the analyzer. The oxygen content in the sample is expressed as .2. The difference between the two measured results obtained by the analyzer for the sample should meet the following requirements: When the oxygen content is less than or equal to 10mL/r, no oxygen content is detected./m oxygen content is greater than /, not greater than half the mean value. Report
The report should include the following content
GB/3396-202
8) Personal information about the sample, such as sample name, batch number, sampling location, sampling month, sampling time, etc.; b) The content of this standard; bzxz.net
4) Determination results,
d) Detailed description of any abnormal phenomenon observed during the determination; e) Name of the analyst and analysis date, etc.
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