This standard specifies the main technical requirements, inspection methods and inspection rules, packaging, storage and other contents of grounding resistance reducing agent. This standard is used for grounding resistance reducing agent to reduce grounding resistance. QX/T 104-2009 Grounding resistance reducing agent QX/T104-2009 Standard download decompression password: www.bzxz.net
This standard specifies the main technical requirements, inspection methods and inspection rules, packaging, storage and other contents of grounding resistance reducing agent. This standard is used for grounding resistance reducing agent to reduce grounding resistance.

ICS07.060
Meteorological Industry Standard of the People's Republic of China
QX/T104—2009
Grounding resistance reduction agent
Grounding resistance reduction agent2009-06-07 Issued
2009-11-01 Implementation
Normative reference documents
Terms and definitions
Main technical requirements for grounding resistance reduction agent
Test methods
Test rules
Packaging and storage of grounding resistance reduction agent
QX/T104—2009
This standard is proposed by the National Technical Committee for Standardization of Meteorological Disaster Prevention and Mitigation (SAC/TC345). This standard is under the jurisdiction of the National Technical Committee for Standardization of Meteorological Disaster Prevention and Mitigation (SAC/TC345). QX/T104—2009
The drafting units of this standard are: Chongqing Lightning Protection Center, School of Resources and Environment of Southwest University, School of Electrical Engineering of Chongqing University. The main drafters of this standard are: Li Liangfu, Li Jiaqi, Qin Binquan, Li Hang, Yuan Tao, Chen Hong, Ren Yan. m
1 Scope
Grounding resistance reducing agent
QX/T104—2009
This standard specifies the main technical requirements, inspection methods and inspection rules, packaging, storage and other contents of grounding resistance reducing agent. This standard applies to grounding resistance reducing agent that reduces the grounding resistance value. Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated referenced documents, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties who 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. GB15618-1995 Soil Environmental Quality Standard NY5010—2002
3 Terms and Definitions
Environmental Conditions for Pollution-free Food and Vegetable Production Areas
The following terms and definitions apply to this standard. 3.1
The grounding resistance reduction agent is a special product that improves the electrical conductivity of the soil near the grounding device, reduces the grounding resistance, and adapts to the grounding device. 3.2
Resistivity
A parameter that characterizes the electrical conductivity of a material, in ohm-meter (Q·m). Note: Rewrite GB/T17949.1—2000, definition 4.19. 3.3
Model coefficient modelcoefficient
The ratio of the length of the test piece to the cross-sectional area under a specific grounding resistance reduction agent test piece structure and size. 3.4
Average corrosion rate per year represents the degree of relatively uniform corrosion of metals, in millimeters per year (mm/a). 3.5
Soil moisture content
The moisture content of the soil.
Technical requirements for grounding resistance reducing agent
4.1 Appearance
The color of the grounding resistance reducing agent should be uniform and free of foreign matter. 4.2 Resistivity
The dry resistivity value of the grounding resistance reducing agent should be less than 5α·m, and the wet resistivity value should be less than 2·m. 4.3 pH
The grounding resistance reduction agent should be neutral or weakly alkaline, and its pH value should be in the range of 7 to 12, preferably 7.8.4.4
Corrosion rate
QX/T104—2009
The corrosion rate of the grounding resistance reduction agent to the grounding body is less than the corrosion rate of the corresponding soil to the grounding body. For hot-dip galvanized round steel and flat steel, the annual average surface corrosion rate should not be greater than 0.03mm/a; for non-galvanized low-carbon round steel and flat steel, the annual average surface corrosion rate should not be greater than 0.05mm/a.
4.5 Impact resistance
The grounding resistance reduction agent should have good resistance to large current impact. After the impact current test, the resistivity increase of the grounding resistance reduction agent sample shall not exceed 20% of the resistivity before the current; after the power frequency current test, the resistivity increase of the grounding resistance reduction agent sample shall not be greater than 20% of the resistivity before the current.
4.6 Physical and chemical properties
The grounding resistance reduction agent should have good water absorption and water retention, and be water-soluble. It should undergo three physical and chemical performance tests: water loss, water immersion, and hot and cold cycles. During and after the test, the test sample should not have dispersion, spontaneous combustion, or volatilization. The resistivity increase of the grounding resistance reduction agent test sample shall not be greater than 20% of the resistivity before the test
4.7 Stability
The grounding resistance reduction agent should pass the stability test. When the soil moisture is similar, the stability test period of the test sample should not be less than four months. During the stability test period, the power frequency grounding resistance value of the test sample grounding body should not exceed 1.2 times the initial test value. 4.8 Environmental protection
4.8.1 The grounding resistance reduction agent should meet environmental protection requirements and should not pollute the soil, water source, air, and environment. 4.8.2 The content of heavy metals and radioactive substances in the grounding resistance reduction agent should meet the requirements of Table 1. Table Controlled amount of heavy metals and radioactive substances in grounding resistance reducing agent (grounding resistance reducing agent dry powder) and detection method Heavy metals and radioactive substances
Radium and its compounds (cd)
Aluminum and its compounds (A)
Mercury and its compounds (Hg)
Lead and its compounds (Pb)
Chromium and its compounds (C
Monument and its compounds (As)
Boron and its compounds (water-soluble B)
Benzo(a)stilbene
Copper and its compounds (Cu)
Zinc and its compounds (Zn)
Nickel and its compounds (Ni)
Hexachlorohexachloride (CHCle)
DDT (CH,Cl)
Test method ||tt| |5.1 Basic provisions
5.1.1 Test sample
Control amount/(mg/kg）
Detection method
Graphite furnace atomic absorption spectrophotometry
Atomic absorption spectrometry
Spectrophotometric colorimetry
Extraction-flame atomic absorption spectrophotometry
Potassium permanganate oxygen, diphenylcarbonyl
Hydrazine photometry
Silver ethyldithiocarbamate spectrophotometry Plasma emission spectrometry
Liquid chromatography
Flame atomic absorption spectrophotometry
Flame atomic absorption spectrophotometry
Flame atomic absorption spectrophotometry
Gas chromatography, silver nitrate turbidimetry
Gas chromatography, nitric acid Silver turbidimetric method
The test samples should be randomly sampled from the normal production batches, and no additives or processing adjustments to the test samples are allowed. The test samples should be placed in the laboratory for no less than 2 hours before inspection to ensure that the test samples are consistent with the laboratory environmental conditions. 5.1.2 Laboratory environmental conditions
Temperature range: 20℃±15℃;
Air pressure range: 86kPa～106kPa;
Humidity range: relative humidity is not more than 60%. 5.1.3 Inspection process
The inspection process is shown in Figure 1.
Resistivity test
Impact resistance test
Power frequency current flow test
5.2 Appearance inspection
Water loss test
Test start
Four copies of the test sample|| tt||Corrosion test
Hot and cold cycle test
Re-prepare
Three copies of the test sample
Water immersion test
Test completion
Stability test
Test process for grounding resistance reduction agent
The grounding resistance reduction agent shall meet the requirements of 4.1 after self-test. 5.3 Resistivity test
5.3.1 Test sample and measurement circuit
QX/T104—2009
Acid and alkalinity test
Environmental protection test
Put the prepared grounding resistance reduction agent into the model according to Figure 2, fill it up and stir it to remove the internal gas, cover it with an insulating cover, place it vertically in a place that is shielded from light and heat source, and let it stand for 1 week as a test sample. The number of test samples is three, and the measurement circuit is shown in Figure 3. Inner electrode
Upper end cover (@10 hot-dip galvanized round steel)
(epoxy resin)
Outer electrode terminal
Outer electrode
(@100 hot-dip galvanized steel pipe)
Lower end cover
(epoxy resin)
Figure 2 Resistivity and power frequency, impact withstand test specimen model diagram Unit is mm
QX/T104—2009
Milliammeter;
Millivoltmeter;
T1, T2, T3-
Transformer.
5.3.2 Measurement method
Variable resistor
Figure 3 Schematic diagram of resistivity measurement
Apply 10mA power frequency current to each test piece at room temperature. When the readings of the millivoltmeter and milliammeter are stable, measure the voltage between the inner and outer electrodes to find the test piece resistance R, and then divide it by the model coefficient 3.67 to obtain the resistivity β of each test piece. Each test piece is tested three times, with a power-off interval of 5min each time. The arithmetic mean of the three test results is taken as the resistivity of the test piece, and the arithmetic mean of the resistivity of the three test pieces is taken as the resistivity p of the grounding resistance reducing agent at room temperature.
Note: Both the millivoltmeter and milliammeter are 0.1-level meters. 5.4 Impulse current withstand test
5.4.1 Test pieces and measurement circuit
The three test pieces after completing the inspection in 5.3 should be subjected to this test within 24h. The experimental circuit is shown in Figure 4. To the charging circuit
Modulation inductor;
Protective resistor;
Discharge gap;
Discharge capacitor:
R1,R2-
5.4.2 Method
Divider resistor.
Oscilloscope
1 Shunt
Figure 4 Schematic diagram of impulse current measurement
Apply 8/20us, 1kA impulse current 20 times to each test piece, each time interval is 1min, each five times as a group, each group interval is 30min. Record the first and 20th discharge currents and the voltage peaks on the test piece. After the test, wait for the test piece to cool to room temperature and measure the power frequency resistance. According to formula (1), calculate the power frequency resistance change rate of each test piece after the test. AR=(Rp-R)/R×100%
Where:
Change rate of power frequency resistance of the test piece after the test;
RB, Re——Power frequency resistance of the test piece before and after the test. .. (1)
Take the arithmetic mean of the power frequency resistance change rates of the three test pieces as the resistance change rate of the test piece's impulse current withstand test, and the result should meet the requirements of 4.5.
QX/T104—2009
Note: Since the model structure size of the test piece does not change before and after the impulse test, the resistance change rate is equivalent to the resistivity change rate. 5.5 Power frequency current flow test
Connect the test piece that has completed the test in 5.4 to Figure 5, apply 10A power frequency current to the test piece five times, each time for 10s, with an interval of 30min, and record the current and voltage values ​​of the first and fifth times. Before and after the withstand test (the sample is cooled to room temperature), measure and record the power frequency resistance of the sample according to 5.3, calculate the resistance change rate of each sample after the power frequency current flow test according to the calculation formula in 5.4.2, and calculate the arithmetic mean of the resistance change rate of the three samples. The entire experiment should be completed within 1 day, and the test results should meet the requirements of 4.5.
Ammeter;
?Voltmeter;
T1.T2.T3-
Transformer.
Figure 5 Schematic diagram of power frequency 10A current flow test
5.6 Physical and chemical performance test
5.6.1 Samples
Put the three samples in an insulation model with an internal size of 80mm×40mm×40mm according to 5.3.1 (see Figure 6). After completion, place them vertically in a place shielded from light and heat source, and let them stand for one week as samples. Upper insulation cover
Insulation box
Resistance reducing agent
5.6.2 Water loss test
Copper electrode
Temperature characteristics and physical and chemical performance test model diagram Measure the power frequency resistance R of the test sample at room temperature according to 5.3, raise the temperature of the constant temperature box to (60±1)℃ for standby, and put the test sample into the constant temperature box at (60±1)℃ for 12h. Then disconnect the power supply of the constant temperature box, open the box door until the test sample cools to room temperature and then take out the test sample. After the test sample cools to room temperature, measure and record the power frequency resistance RH of the test sample according to the method in 5.3, and calculate the resistivity pH of each test sample after inspection according to formula (2). www.bzxz.net
PH=R·Pp/Rr
Where:
Resistivity of the test sample at room temperature.
·（2）
After the resistivity of each test sample is obtained according to the above formula, the arithmetic mean value is taken as the resistivity of the grounding resistance reducing agent after the water loss test. The resistivity change before and after the test should meet the requirements of 4.6. 5.6.3 Hot and cold cycle test
Place the three test samples after the water loss test in a special container, soak them for 24 hours, take them out and drain them for 24 hours, measure the power frequency resistance according to 5.3, and perform hot and cold cycle test according to Figure 7. After the test, put the test sample into water and soak it for 24 hours, take it out and drain it for 24 hours, and then measure the resistance at power frequency 10mA according to 5.3.
120℃
-10℃
120℃
-10℃
Figure 7 Hot and cold cycle program
Immerse in water for 24h
According to formula (2), calculate the resistivity of the three samples after the hot and cold cycle test respectively, and then calculate the arithmetic mean of the resistivity of the three samples. The result should meet the requirements of 4.6
5.6.4 Water immersion test
Prepare the sample again according to Figure 6, and let it stand for one week as the sample. Put the sample vertically into the container, add water to the container to the water level line of 120mm, place it in a place without light and heat source, take it out after soaking for 24h, and measure the power frequency resistance according to 5.3 as the resistance before the test. Place the sample in a container and soak for 27 days. Change the water after 24 hours, and then change the water every 2 days. Then take the sample out of the water and drain for 30 minutes. Measure the power frequency resistance according to the method in 5.3 as the resistance of the sample after water immersion test. At the same time, observe whether the sample is loose and cracked. After the test is completed, calculate the resistivity of the three samples after water immersion test according to formula (2). Take the arithmetic mean of the resistivity of the three samples. The result should meet the requirements of 4.6.
5.7 Corrosion test of metal grounding electrode
5.7.1 Grounding electrode test pieces
Each group of test pieces consists of 40 test pieces, including 10 test pieces of hot-dip galvanized round (flat) steel and 10 test pieces of non-galvanized low-carbon round (flat) steel; the flat steel test piece is 25mm wide and the thickness is not less than 100
2.5mm after being scrubbed clean; the round steel test piece is 10mm in diameter and the length of each test piece is 50mm. The test piece should be derusted and dried in a thermostatic box with alcohol at 1℃ for 1h, cooled to room temperature, and then weighed with a 0.1mg sensitive balance for use. 5.7.2 Corrosion test of indoor grounding resistance reducing agent on metal grounding electrode Take a group of samples and put them in the sample box shown in Figure 8. First, spread a 40mm thick resistance reducing agent on the bottom of the box, place the samples, and the spacing should be greater than 60cm, and then cover the samples with a 40mm thick resistance reducing agent. After 1h of placement, spray distilled water on the surface of the sample box until the surface water reaches 5mm, and then wrap the sample box tightly with a double layer of plastic film to prevent water evaporation. Unit: mm
25×3 non-galvanized flat steel
25×3 galvanized flat steel
810 galvanized round steel
>31000
>600>600
Figure 8 Month
Schematic diagram of buried corrosion test specimens
The specimen box should be placed in a place without heat source and direct sunlight for no less than 120d. 6
810 non-galvanized round steel
Specimen box
Grounding resistance reducing agent
QX/T104—2009
Take out the specimens after 120d, weigh them one by one after cleaning and derusting, and calculate the corrosion rate according to formula (3). The corrosion rates of hot-dip galvanized steel and non-galvanized steel should be counted separately, and the value is the average value of each specimen. V=（△W/S·t）·(3650/d)
Where:
average annual corrosion rate of the specimen surface, in millimeters per year (mm/a); —weight loss of the specimen, in grams (g);
surface area of ​​the specimen, in square centimeters (cm); S
number of days the specimen is buried in the resistance reduction agent, in days (d); d
specific gravity of the specimen material, in grams per cubic meter (g/cm). The corrosion test results of the grounding resistance reduction agent on the metal grounding electrode shall comply with the requirements of Article 4.4. 5.7.3 Corrosion test of the grounding resistance reduction agent on the metal grounding electrode when buried outdoors (3)
This test is carried out in outdoor soil. The buried site should not be prone to water accumulation. The depth of the test pit is 600mm~700mm. The method and requirements for burying the specimen are the same as those in 5.7.2. After the upper layer of grounding resistance reduction agent is placed on the trench surface and smoothed, leave it for 1 hour and then backfill the soil and compact it. Take it out after 120 days and calculate the average annual corrosion rate of the test piece surface according to formula (3). The test result should meet the requirements of Article 4.4. 5.8 Stability test
Three 2m long horizontal grounding devices of the same material are buried in the same characteristic soil area with a burial depth of 6m. After using the resistance reducing agent, the grounding resistance tester is used to test the grounding resistance. The grounding resistance is measured once within 2d to 5d after burial, which is used as the initial grounding resistance R. Then the grounding resistance value R is measured at regular intervals, and at least four times. The number of grounding resistance measurements between them is not less than six times. The time interval between each test and the previous test is not less than 10d, and the soil wall conditions during each test should be consistent. According to formula (4), the change rate of the power frequency grounding resistance of the three horizontal grounding devices is calculated. AR=(R,-R)/R. X100%
Where:
Power frequency grounding resistance change rate;
Power frequency grounding resistance (Q) for each test, which is the number of times. R4
.·(4)
Take the arithmetic mean of the grounding resistance change rate of the three horizontal grounding devices as the resistance change rate for the stability test of the resistance reducing agent, and the result should meet the requirements of 4.7
5.9 pH measurement
Weigh three dried grounding resistance reducing agents as test samples, 20g ± 0.1g each, and pour them into three clean and dry glass measuring cups respectively. Add 20mL of distilled water to each portion, stir for 2min, let stand for 30min, and filter with ordinary qualitative filter paper with a pore size of 11uμm and a conical glass funnel. The filtrate is used as the test solution. Use an acidometer to measure the pH value. Take the pH average of the three test solutions as the pH measurement value of the grounding resistance reducing agent.
5.10 Environmental protection test
The controlled amount of heavy metals and radioactive substances is shown in Table 1. The test method should comply with the provisions of the "Environmental Testing and Analysis Methods" and "Modern Analysis Methods of Soil Elements" promulgated by the former State Environmental Protection Administration. Inspection rules
6.1 Inspection classification
The inspection of grounding resistance reduction agent is divided into factory inspection and type inspection. 6.2 Factory inspection
Before leaving the factory, the grounding resistance reduction agent shall randomly select no less than three packages from each batch for appearance inspection. On the basis of passing the inspection, other items shall be inspected for factory inspection. If any item fails, the product shall fail the factory inspection. QX/T104—2009
Type inspection
Type inspection shall randomly select three packages from the products that pass the factory inspection and inspect them according to the type inspection items in Table 2. If any one of the technical requirements fails, it shall be judged as unqualified. Table 2
Inspection items
Inspection items
Experimental requirements
Type inspection
Appearance inspection
Room temperature resistivity measurement
Impact current withstand test
Power frequency current withstand test
Physical and chemical performance test
Corrosion test
Stability test
Acidity and alkalinity
Environmental protection test
Packaging and storage of grounding resistance reducing agent
Factory inspection
Experimental method
Grounding resistance reducing agent should be double-layer packaged to ensure that the product is not damaged during transportation due to poor packaging. The grounding resistance reducing agent packaging should indicate:
a) Manufacturer name, product name and model; b) Product weight, production date and shelf life. Technical documents provided with the product
a) Product factory certificate;
b) Instructions for use.
The product should be stored in a cool and dry place indoors to prevent moisture, rain and water immersion.
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