This standard specifies the Karl Fischer coulometric method and the hygrometer method for the determination of trace water in ethylene and propylene. GB/T 3727-2003 Determination of trace water in industrial ethylene and propylene GB/T3727-2003 Standard download decompression password: www.bzxz.net

GB/T 3727--2003
This standard adopts the Russian version of IOCT24975.5:1991 "Method for the determination of trace water in ethylene and propylene" (non-equivalent). The main differences between this standard and IOCT24975.5:1991 are as follows: a) In the meter method, it is clarified that the electrolytic hygrometer is not suitable for the determination of trace water in propylene, a method summary is added, and the appendix "Industrial Hygrometer" is deleted;
b) The Karl Fischer coulometric method is used instead of the Karl Fischer volumetric method; c) The capillary tube is used instead of the injection pipeline and flow control valve, and the contents of "Analysis Preparation" and "Analysis Process" are revised accordingly; d) The determination range of the Karl Fischer method is adjusted from "not less than 0.001%" to not less than 1 mg/kg". This standard replaces GB/T3727-1983 "Determination of Trace Water in Polymerization Grade Ethylene and Propylene by Karl Fischer Method". The main changes of this standard compared with GB/T3727--1983 are as follows: a) The name of the standard is changed to "Determination of Trace Water in Industrial Ethylene and Propylene" Determination of trace water"; b) Added the content of the determination of trace water in ethylene and propylene by hygrometer method; replaced the Karl Fischer volumetric method of the original standard with the Karl Fischer coulometric method; replaced the injection line and flow regulating valve of the original standard with a capillary, and revised the content of the "Operation Steps" accordingly; d)
e) The determination range of the Karl Fischer method was adjusted from "5mL/m2～150ml./m3\ to not less than 1mg/kg". This standard was proposed by China Petroleum and Chemical Corporation. This standard is under the jurisdiction of the Petrochemical Technical Committee of the National Chemical Standardization Committee (SAC/TC63/SC4). This standard was drafted by Shanghai Petrochemical Research Institute of China Petroleum and Chemical Corporation. The main drafters of this standard are: Wang Chuan, Zhang Wei, Ye Zhiliang. The previous versions of the standards replaced by this standard are: GB/T 3727-1983.
1 Scope
Determination of trace water in industrial ethylene and propylene GB/T 3727—2003
1.1 This standard specifies the Karl Fischer coulometric method and the hygrometer method for the determination of trace water in ethylene and propylene. The Karl Fischer coulometric method of this standard is applicable to the determination of trace water with a content of not less than 1 mg/kg, and the hygrometer method is applicable to the determination of trace water with a content of not less than 1 mL/m2. 1.2 This standard does not intend to address all safety issues associated with its use. Therefore, the user of this standard shall be responsible for establishing appropriate safety and protection measures in advance and determining appropriate rules and regulations. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For all referenced documents with dates, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties that reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all undated referenced documents, the latest versions are applicable to this standard. GB/T2366--1986 Determination of moisture content in chemical products-Gas chromatography method GB/T8 170--1987 Rules for rounding off values ​​
GB/T13289-1991 Sampling method for liquid and gaseous ethylene for industrial use GB/T13290-1991 Sampling method for liquid propylene and butadiene for industrial use 3 Karl Fischer coulometric method
3.1 Summary of the method
When the gas to be measured passes through the electrolytic cell of the Karl Fischer coulometric analyzer, the water in the gas reacts with the iodine and sulfur dioxide in the Karl Fischer reagent in the presence of an organic base (such as pyridine) and methanol to produce the following reaction: H2O+I2 +SO2+CH,OH+3RN
--→(RNH)SO,CH +2(RNH)I
The consumed iodine is replenished by electrolysis of the anolyte containing iodide ions: 2I-→I2+2e
The amount of iodine required for the reaction is proportional to the amount of electricity passing through the electrolytic cell. Therefore, the amount of electricity consumed by the electrolysis is recorded, and the water content in the sample can be calculated according to Faraday's law of electrolysis.
3.2 Instruments and equipment
3.2.1 Karl Fischer coulometer: the detection limit should not be higher than 10μg3.2.2 Electronic balance:
a) Sensitivity 0.1g or 0.01g, the weighing range should meet the requirements of 3.2.5 and 3.2.6 cylinder weighing; b) Sensitivity 0.1mg, weighing range (0~160)g;3.2.3 Air drying oven;
3.2.4 Water bath;
3.2.5 Ethylene injection cylinder: 1000mL, in accordance with GB/T13289, the inner wall should be polished, and the outlet end should be equipped with a pressure gauge with a range of (0~16)MPa;
3.2.6 Propylene injection cylinder: 1000mL, in accordance with GB/T13290, the inner wall should be polished. 3.3 Reagents and materials
3.3.1 Elastic quartz capillary:
a) Inner diameter (0.25±0.01) mm, length (2.0±0.1) m, for propylene analysis;1
GB/T3727—2003
b) Inner diameter (0.15±0.01) mm, length (3.0±0.1) m, for ethylene analysis;3.3.2 Micro syringe: 100μL;
3.3.3 Medical injection needle: No. 9;
3.3.4 Tightening nut;
3 .3.5 Stainless steel ferrule: middle hole, hole diameter 1.5mm3.3.6 Sealing pad: silicone rubber;
3.3.7 Plastic septum: polytetrafluoroethylene, middle hole, hole diameter 1.5mm;3.3.8 Benzene-water equilibrium solution: prepared according to 5.2.1 of GB/T2366-1986;3.3.9 Karl Fischer coulometric electrolyte (cathodic liquid, anodic liquid);3.3.10 Ethylene glycol: water mass fraction not more than 0.05%;3.3.11 Nitrogen: volume fraction not less than 99.999%, water content not more than 3ml/m3.3.4 Sample
Before sampling, the cylinder (3.2.5, 3.2.6) should be kept clean and dry. Take liquid samples according to the technical requirements of GB/T13289-1991 and GB/T13290-1991.
Note: The cleaned and dried cylinder can be placed in a blast drying oven at 110℃ and ventilated with nitrogen (3.3.11) for 30 minutes to obtain a better drying effect. 3.5 Sample determination
3.5.1 Analysis preparation
3.5.1.1 Prepare the instrument according to the instrument manual, and fill the electrolytic cell with Karl Fischer cathode solution and anode solution (3.3.9), with the liquid level slightly below the electrolytic cell injection port.
Note: The anode solution contains an appropriate amount of ethylene glycol (such as 10% of the total volume) to help absorb trace water in the sample. 3.5.1.2 Turn on the instrument and perform a blank titration to prepare for injection. 3.5.1.3 Karl Fischer coulometer performance check: Use a micro syringe (3.3.2) to draw (50-60) μI of benzene-water equilibrium solution (3.3.8) and inject it into the electrolytic cell for titration. Use an electronic balance (3.2.2b) to accurately weigh the added benzene-water equilibrium solution by differential subtraction. Repeat the measurement twice and calculate its average water content (the difference between the two measurement results should not exceed 5% of its average value). The relative error between this value and the theoretical water content of the benzene-water equilibrium solution (see Table 1 in GB/T2366-1986) should not exceed ±10%. 3.5.1.4 After sampling, let the injection cylinder stand at room temperature, wipe off the condensed water on the surface, and ensure that the cavity of the gas outlet connected to the capillary is fully dry.
3.5.1.5 Check the pressure of the ethylene injection cylinder, which should not exceed 8MPa. Otherwise, discharge the excess sample according to the requirements of GB/T13289-1991. 3.5.2 Determination steps
3.5.2.1 Assemble the sample cylinder (3.2.5, 3.2.6), cylinder stand, electronic balance (3.2.2a), quartz capillary (3.3.1), Karl Fischer coulometer (3.2.1), and water bath as shown in Figure 1. Coil the capillary (3.3.1) into a ring shape and immerse it in a water bath at 30℃ to 40℃. Insert one end of the capillary into the medical injection needle (3.3.3), and insert the compression nut (3.3.4), stainless steel ferrule (3.3.5), sealing gasket (3.3.6) and plastic septum (3.3.7) in sequence, and then connect it to the gas outlet of the sample cylinder (see Figure 1). After the connection is completed, pull out the injection needle and leave the capillary in the sealing gasket. Insert the other end of the capillary into the medical injection needle (3.3.3), and insert it into the rubber septum of the injection port of the Karl Fischer coulometer electrolytic cell. Keep the capillary port above the anode liquid level, pull out the injection needle, and leave the capillary in the rubber septum of the injection port. Note 1: Other capillary gasification devices and connection methods that can meet the technical requirements of this standard can also be used. Note 2: When measuring ethylene, the end of the cylinder without a pressure gauge should be used as the outlet and connected to the capillary. 3.5.2.2. Open the gas outlet valve of the injection cylinder to allow the sample to flow out and gasify, purge the injection system (the purge time is at least 40 minutes for ethylene and at least 30 minutes for propylene), insert the capillary port at one end of the electrolytic cell into the bottom of the electrolytic cell, continue to purge for 5 minutes, and then close the cylinder valve. 3.5.2.3 After the instrument enters the measurement state, use an electronic balance (3.2.2a) to accurately weigh the injection cylinder. Open the cylinder valve to inject the sample, and control the injection volume according to the table below. After the injection, close the cylinder valve and start the titration switch for titration. After the injection is completed, accurately weigh the injection cylinder again. The difference between the two weighings is the sample mass. After the titration is completed, record the measured moisture content. Water content of sample/(mg/kg）
Injection volume/g
5～10
GB/T3727-—2003
Note: During the determination of propylene, the cylinder valve does not need to be opened or closed. Instead, the injection is controlled by controlling the inlet and outlet of the capillary. When injecting, slowly insert the capillary into the cylinder connection port. After the injection is completed, carefully pull out the capillary at the outlet end of the cylinder so that the capillary port remains in the sealing gasket. 13
Electronic balance;
Cylinder holder;
Sampling cylinder;
Capillary:
Water bath;
Drying tube;
Electrolytic cell;
8 Karl Fischer coulometer main unit,
Sampling cylinder port;
Plastic septum;
-sealing gasket;
Compression nut:
Stainless steel ferrule. bzxz.net
Figure 1 Schematic diagram of the assembly of the Karl Fischer coulometric instrument and the connection port of the cylinder capillary 3.6
Result presentation
The water content (ci) in the sample is expressed as mass concentration (mg/kg) and calculated according to formula (1): 3. 6. 1
Wherein:
-absolute value of water displayed by the instrument, ug;
-mass of the sample, g.
3.6.2The water content (c2) in the sample is expressed as volume concentration (mL/m2) and calculated according to formula (2): (1)
GB/T3727—2003
Wherein:
ca ×ioi
M-relative molecular weight of ethylene or propylene (28.05 for ethylene and 42.08 for propylene); 18.01-relative molecular weight of water.
3.6.3 Take the arithmetic mean of the results of two repeated measurements as the analysis result, and round it to 0.1 mg/kg according to the provisions of GB/T81701987.
3.7 Repeatability
In the same laboratory, by the same operator, using the same instrument and equipment, the same sample with a moisture content in the range of 1 mg/kg to 50 mg/kg is repeatedly measured twice in succession. Under the condition of 95% confidence level, the difference between the results obtained should not be greater than 3 mg/kg. 4 Hygrometer method
4.1 Summary of the method
4.1.1 Capacitive hygrometer
When the measured gas passes through the capacitive sensor composed of an aluminum oxide electrolyte layer and an aluminum substrate, the moisture in the gas is absorbed by the aluminum oxide layer, causing the capacitance of the sensor to change, and the water content is measured accordingly. 4.1.2 Piezoelectric hygrometer
When the measured gas passes through a piezoelectric sensor composed of a quartz crystal and a hygroscopic layer deposited on its surface, the moisture in the gas is absorbed by the hygroscopic layer, changing the mass of the quartz crystal, thereby changing the vibration frequency of the quartz crystal, and the water content is measured accordingly. 4.1.3 Electrolytic hygrometer
When the measured gas passes through an electrolytic sensor composed of two parallel platinum wires and phosphorus pentoxide coated on its surface, the moisture in the gas is absorbed by phosphorus pentoxide to form phosphoric acid, and the following reaction occurs under the action of an external DC voltage: 4H.P04—→2P,0,+302+6H2
The electrolytic current is accurately measured, and the water content is measured accordingly. Since propylene is prone to polymerization under acidic conditions, this type of hygrometer is not suitable for the determination of trace water in propylene.
4.2 Instruments, equipment and materials
4.2.1 Hygrometer: The detection limit should not be higher than 1 mL/m24.2.2 Water bath;
4.2.3 Flowmeter: The measuring range should meet the flow range required by the hygrometer. 4.3 Sampling
The hygrometer can be directly connected to the sampling pipeline. If cylinder sampling is required, follow 3.4. 4.4 Sample determination
4.4.1 Instrument connection (see Figure 2)
4.4.1.1 Pipeline connection of the measuring device: To prevent water in the atmosphere from penetrating into the gas path, all connecting pipelines should be made of stainless steel. Copper tubes, polytetrafluoroethylene tubes and polyethylene tubes can also be used. If the sample gas needs to be vented, a vent pipe no shorter than 2 m should be connected to the outlet of the measuring device to prevent the reverse diffusion of water in the atmosphere and cause the analysis results to be higher. 4.4.1.2 Pressure regulation of gaseous samples: Use stainless steel pipe to connect the hygrometer and sample cylinder or sampling pipeline. If necessary, a metal diaphragm pressure reducing valve can be used to adjust the pressure of the sample gas.
4.4.1.3 Evaporation and gasification of liquid samples: When converting liquid samples to gaseous state, they must be decompressed first and then enter the evaporator heated by hot water or steam to completely evaporate the sample and ensure that the temperature of the gaseous sample is not lower than 15°C. 4.4.1.4 The gaseous sample entering the measurement chamber must not contain dust particles or water droplets. It can be filtered with a stainless steel sintered sand core (pore size of 5um~7μm) to remove dust particles
Gas inlet
-water bath;
Spiral stainless steel pipe;
Flow regulating valve;
Sampling unit;
Hygrometer;
-Vent pipe;
Flowmeter.
4.4.2 Check of connecting pipes
Figure 2 Schematic diagram of instrument assembly for hygrometer method
Before the formal measurement, check whether the connecting pipes and joints are leaking. 4.4.3 Sample measurement
GB/T3727—2003
Exhaust port
Connect the pipes as described in 4.4.1, prepare the instrument and adjust the working parameters according to the instrument instructions, and introduce the gaseous sample at the specified flow rate. After the hygrometer indication stabilizes, read and record. 4.5 Expression of results
4.5.1 Record the reading indicated by the hygrometer and express the water content in the sample as volume concentration (mL/m). 4.5.2 The measurement results shall be rounded to 0.1mL/m according to the provisions of GB/T8170—1987. 4.6 Calibration
Calibrate the hygrometer according to the instrument instructions. The calibration method may adopt the Karl Fischer method or other appropriate methods that can ensure accuracy. 5 Report
The report should include the following contents:
a) All information about the sample, such as sample name, batch number, sampling location, sampling date, sampling time, etc.;
The code of this standard and the measurement method
Measurement results;
Details and explanation of any abnormal phenomena observed during the measurement; Name of the analyst and analysis date, etc.1
Where:
-absolute value of water content displayed by the instrument, ug;
-mass of sample, g.
3.6.2 Express the water content (c2) in the sample as volume concentration (mL/m2) and calculate according to formula (2): (1)
GB/T3727—2003
Where:
ca ×ioi
M-relative molecular weight of ethylene or propylene (28.05 for ethylene and 42.08 for propylene); 18.01-relative molecular weight of water.
3.6.3 Take the arithmetic mean of the results of two repeated measurements as the analysis result and round it off to 0.1 mg/kg according to the provisions of GB/T81701987.
3.7 Repeatability
In the same laboratory, by the same operator, using the same instrument and equipment, the same sample with a moisture content in the range of 1mg/kg to 50mg/kg is measured twice in succession. Under the condition of 95% confidence level, the difference between the results should not be greater than 3mg/kg. 4 Hygrometer method
4.1 Summary of the method
4.1.1 Capacitive hygrometer
When the measured gas passes through the capacitive sensor composed of an aluminum oxide electrolyte layer and an aluminum matrix, the moisture in the gas is absorbed by the aluminum oxide layer, causing the capacitance of the sensor to change, and the water content is measured accordingly. 4.1.2 Piezoelectric hygrometer
When the measured gas passes through the piezoelectric sensor composed of a quartz crystal and a hygroscopic layer deposited on its surface, the moisture in the gas is absorbed by the hygroscopic layer, changing the mass of the quartz crystal, thereby causing the vibration frequency of the quartz crystal to change, and the water content is measured accordingly. 4.1.3 Electrolytic hygrometer
When the measured gas passes through the electrolytic sensor composed of two parallel platinum wires and phosphorus pentoxide coated on its surface, the water in the gas is absorbed by phosphorus pentoxide to form phosphoric acid. Under the action of an external DC voltage, the following reaction occurs: 4H.P04—→2P,0,+302+6H2
Accurately measure the electrolytic current and measure the water content accordingly. Since propylene is prone to polymerization under acidic conditions, this type of hygrometer is not suitable for the determination of trace water in propylene.
4.2 Instruments, equipment and materials
4.2.1 Hygrometer: The detection limit should not be higher than 1 mL/m24.2.2 Water bath;
4.2.3 Flowmeter: The range should meet the flow range required by the hygrometer. 4.3 Sampling
The hygrometer can be directly connected to the sampling pipeline. If cylinder sampling is required, follow 3.4. 4.4 Sample measurement
4.4.1 Instrument connection (see Figure 2)
4.4.1.1 Pipeline connection of measuring device: To prevent water in the atmosphere from penetrating into the gas path, all connecting pipelines should be made of stainless steel. Copper tubes, polytetrafluoroethylene tubes and polyethylene tubes can also be used. If the sample gas needs to be vented, a vent pipe of not less than 2 m should be connected at the outlet of the measuring device to prevent the reverse diffusion of water in the atmosphere and cause the analysis result to be too high. 4.4.1.2 Pressure regulation of gaseous samples: Use stainless steel pipes to connect the hygrometer and sample cylinder or sampling pipeline. If necessary, a metal diaphragm pressure reducing valve can be used to adjust the pressure of the sample gas.
4.4.1.3 Evaporation and gasification of liquid samples: When converting liquid samples to gaseous state, they must first be decompressed and then enter the evaporator heated by hot water or steam to completely evaporate the sample and ensure that the temperature of the gaseous sample is not lower than 15°C. 4.4.1.4 The gaseous sample entering the measuring room shall not contain dust particles or water droplets. It can be filtered with a stainless steel sintered sand core (pore size is 5um~7μm) to remove dust particles.
Gas inlet
-water bath;
Spiral stainless steel pipe;
Flow regulating valve;
Sampling unit;
Hygrometer;
-Vent pipe;
Flowmeter.
4.4.2 Check of connecting pipelines
Figure 2 Schematic diagram of assembly of hygrometer method instrument
Before the formal measurement, check whether the connecting pipelines and joints are leaking. 4.4.3 Sample determination
GB/T3727—2003
Exhaust port
Connect the pipeline as described in 4.4.1, prepare the instrument and adjust the working parameters according to the instrument instructions, and introduce the gaseous sample at the specified flow rate. After the hygrometer indication stabilizes, read and record the reading. 4.5 Expression of results
4.5.1 Record the reading indicated by the hygrometer and express the water content in the sample as volume concentration (mL/m). 4.5.2 The determination result shall be rounded to 0.1mL/m according to the provisions of GB/T8170—1987. 4.6 Calibration
Calibrate the hygrometer according to the instrument instructions. The calibration method may be the Karl Fischer method or other appropriate methods that can ensure accuracy. 5 Report
The report should include the following contents:
a) All information about the sample, such as sample name, batch number, sampling location, sampling date, sampling time, etc.;
The code of this standard and the measurement method
Measurement results;
Details and explanation of any abnormal phenomena observed during the measurement; Name of the analyst and analysis date, etc.1
Where:
-absolute value of water content displayed by the instrument, ug;
-mass of sample, g.
3.6.2 Express the water content (c2) in the sample as volume concentration (mL/m2) and calculate according to formula (2): (1)
GB/T3727—2003
Where:
ca ×ioi
M-relative molecular weight of ethylene or propylene (28.05 for ethylene and 42.08 for propylene); 18.01-relative molecular weight of water.
3.6.3 Take the arithmetic mean of the results of two repeated measurements as the analysis result and round it off to 0.1 mg/kg according to the provisions of GB/T81701987.
3.7 Repeatability
In the same laboratory, by the same operator, using the same instrument and equipment, the same sample with a moisture content in the range of 1mg/kg to 50mg/kg is measured twice in succession. Under the condition of 95% confidence level, the difference between the results should not be greater than 3mg/kg. 4 Hygrometer method
4.1 Summary of the method
4.1.1 Capacitive hygrometer
When the measured gas passes through the capacitive sensor composed of an aluminum oxide electrolyte layer and an aluminum matrix, the moisture in the gas is absorbed by the aluminum oxide layer, causing the capacitance of the sensor to change, and the water content is measured accordingly. 4.1.2 Piezoelectric hygrometer
When the measured gas passes through the piezoelectric sensor composed of a quartz crystal and a hygroscopic layer deposited on its surface, the moisture in the gas is absorbed by the hygroscopic layer, changing the mass of the quartz crystal, thereby causing the vibration frequency of the quartz crystal to change, and the water content is measured accordingly. 4.1.3 Electrolytic hygrometer
When the measured gas passes through the electrolytic sensor composed of two parallel platinum wires and phosphorus pentoxide coated on its surface, the water in the gas is absorbed by phosphorus pentoxide to form phosphoric acid. Under the action of an external DC voltage, the following reaction occurs: 4H.P04—→2P,0,+302+6H2
Accurately measure the electrolytic current and measure the water content accordingly. Since propylene is prone to polymerization under acidic conditions, this type of hygrometer is not suitable for the determination of trace water in propylene.
4.2 Instruments, equipment and materials
4.2.1 Hygrometer: The detection limit should not be higher than 1 mL/m24.2.2 Water bath;
4.2.3 Flowmeter: The range should meet the flow range required by the hygrometer. 4.3 Sampling
The hygrometer can be directly connected to the sampling pipeline. If cylinder sampling is required, follow 3.4. 4.4 Sample measurement
4.4.1 Instrument connection (see Figure 2)
4.4.1.1 Pipeline connection of measuring device: To prevent water in the atmosphere from penetrating into the gas path, all connecting pipelines should be made of stainless steel. Copper tubes, polytetrafluoroethylene tubes and polyethylene tubes can also be used. If the sample gas needs to be vented, a vent pipe of not less than 2 m should be connected at the outlet of the measuring device to prevent the reverse diffusion of water in the atmosphere and cause the analysis result to be too high. 4.4.1.2 Pressure regulation of gaseous samples: Use stainless steel pipes to connect the hygrometer and sample cylinder or sampling pipeline. If necessary, a metal diaphragm pressure reducing valve can be used to adjust the pressure of the sample gas.
4.4.1.3 Evaporation and gasification of liquid samples: When converting liquid samples to gaseous state, they must first be decompressed and then enter the evaporator heated by hot water or steam to completely evaporate the sample and ensure that the temperature of the gaseous sample is not lower than 15°C. 4.4.1.4 The gaseous sample entering the measuring room shall not contain dust particles or water droplets. It can be filtered with a stainless steel sintered sand core (pore size is 5um~7μm) to remove dust particles.
Gas inlet
-water bath;
Spiral stainless steel pipe;
Flow regulating valve;
Sampling unit;
Hygrometer;
-Vent pipe;
Flowmeter.
4.4.2 Check of connecting pipelines
Figure 2 Schematic diagram of assembly of hygrometer method instrument
Before the formal measurement, check whether the connecting pipelines and joints are leaking. 4.4.3 Sample determination
GB/T3727—2003
Exhaust port
Connect the pipeline as described in 4.4.1, prepare the instrument and adjust the working parameters according to the instrument instructions, and introduce the gaseous sample at the specified flow rate. After the hygrometer indication stabilizes, read and record the reading. 4.5 Expression of results
4.5.1 Record the reading indicated by the hygrometer and express the water content in the sample as volume concentration (mL/m). 4.5.2 The determination result shall be rounded to 0.1mL/m according to the provisions of GB/T8170—1987. 4.6 Calibration
Calibrate the hygrometer according to the instrument instructions. The calibration method may be the Karl Fischer method or other appropriate methods that can ensure accuracy. 5 Report
The report should include the following contents:
a) All information about the sample, such as sample name, batch number, sampling location, sampling date, sampling time, etc.;
The code of this standard and the measurement method
Measurement results;
Details and explanation of any abnormal phenomena observed during the measurement; Name of the analyst and analysis date, etc.4 The gaseous sample entering the measuring room shall not contain dust particles or water droplets. It can be filtered with a stainless steel sintered sand core (pore size is 5um~7μm) to remove dust particles
Gas inlet
-water bath;
Spiral stainless steel pipe;
Flow regulating valve;
Sampling unit;
Hygrometer;
-Vent pipe;
Flowmeter.
4.4.2 Check of connecting pipelines
Figure 2 Schematic diagram of assembly of hygrometer method instrument
Before the formal measurement, check whether the connecting pipelines and joints are leaking. 4.4.3 Sample determination
GB/T3727—2003
Exhaust port
Connect the pipeline as described in 4.4.1, prepare the instrument and adjust the working parameters according to the instrument instructions, and introduce the gaseous sample at the specified flow rate. After the hygrometer indication stabilizes, read and record the reading. 4.5 Expression of results
4.5.1 Record the reading indicated by the hygrometer and express the water content in the sample as volume concentration (mL/m). 4.5.2 The determination result shall be rounded to 0.1mL/m according to the provisions of GB/T8170—1987. 4.6 Calibration
Calibrate the hygrometer according to the instrument instructions. The calibration method may be the Karl Fischer method or other appropriate methods that can ensure accuracy. 5 Report
The report should include the following contents:
a) All information about the sample, such as sample name, batch number, sampling location, sampling date, sampling time, etc.;
The code of this standard and the measurement method
Measurement results;
Details and explanation of any abnormal phenomena observed during the measurement; Name of the analyst and analysis date, etc.4 The gaseous sample entering the measuring room shall not contain dust particles or water droplets. It can be filtered with a stainless steel sintered sand core (pore size is 5um~7μm) to remove dust particles
Gas inlet
-water bath;
Spiral stainless steel pipe;
Flow regulating valve;
Sampling unit;
Hygrometer;
-Vent pipe;
Flowmeter.
4.4.2 Check of connecting pipelines
Figure 2 Schematic diagram of assembly of hygrometer method instrument
Before the formal measurement, check whether the connecting pipelines and joints are leaking. 4.4.3 Sample determination
GB/T3727—2003
Exhaust port
Connect the pipeline as described in 4.4.1, prepare the instrument and adjust the working parameters according to the instrument instructions, and introduce the gaseous sample at the specified flow rate. After the hygrometer indication stabilizes, read and record the reading. 4.5 Expression of results
4.5.1 Record the reading indicated by the hygrometer and express the water content in the sample as volume concentration (mL/m). 4.5.2 The determination result shall be rounded to 0.1mL/m according to the provisions of GB/T8170—1987. 4.6 Calibration
Calibrate the hygrometer according to the instrument instructions. The calibration method may be the Karl Fischer method or other appropriate methods that can ensure accuracy. 5 Report
The report should include the following contents:
a) All information about the sample, such as sample name, batch number, sampling location, sampling date, sampling time, etc.;
The code of this standard and the measurement method
Measurement results;
Details and explanation of any abnormal phenomena observed during the measurement; Name of the analyst and analysis date, etc.
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