National Standard Indoor Air Quality Standard 1/2
1. Scope
This standard outlines the parameters for indoor air quality and the corresponding testing methods. It is applicable to both residential and office buildings, ensuring that indoor environments meet acceptable health and comfort levels.
2. Normative References
The following documents are referenced in this standard. For dated references, only the editions listed apply unless otherwise stated. For undated references, the latest version should be used. These standards provide the technical basis for measuring various pollutants in indoor air:
GB 6921-86 – Gravimetric method for determining airborne dust concentration
GB 9801-88 – Non-dispersive infrared method for carbon monoxide determination
GB 11737-89 – Gas chromatography method for benzene, toluene, and xylene in residential areas
GB 12372-90 – Improved Saltzman method for nitrogen dioxide in residential air
GB/T 14679-93 – Sodium hypochlorite-salicylic acid spectrophotometric method for ammonia
GB/T 14669-93 – Ion selective electrode method for ammonia
GB/T 14582-93 – Helium measurement in ambient air
GB 14677-93 – Gas chromatography for toluene, xylene, and styrene
GB/T 15262-94 – Formaldehyde absorption - Pararosaniline photometric method for sulfur dioxide
GB/T 15435-1995 – Saltzman method for nitrogen dioxide
GB/T 15438-1995 – UV spectrophotometric method for ozone
GB/T 15439-1995 – High-performance liquid chromatography for benzo[a]pyrene
GB/T 15516-1995 – Acetylacetone spectrophotometric method for formaldehyde
GB/T 16128-1995 – Formaldehyde absorption - Pararosaniline hydrochloride method for sulfur dioxide
GB/T 16129-1995 – Spectrophotometric method for formaldehyde in residential air
GB/T 16146-1995 – Concentration control standard for housing
GB/T 16147-1995 – Scintillation flask method for radon concentration
GB/T 17095-1997 – Sanitary standards for inhalable particles in indoor air
GB/T 18204.18-2000 – Tracer gas method for measuring indoor air volume
GB/T 18204.23-2000 – Carbon monoxide test method for public places
GB/T 18204.24-2000 – Carbon dioxide test method for public places
GB/T 18204.25-2000 – Ammonia test method for public places
GB/T 18204.26-2000 – Formaldehyde determination in public places
GB/T 18204.27-2000 – Ozone inspection method for public places
5. Indoor Air Quality Inspection
5.1 Sampling and testing methods for various chemical pollutants in indoor air are detailed in Appendix A and B.
5.2 Benzene concentration in indoor air is described in Appendix C.
5.3 Methods for determining total volatile organic compounds (TVOC) are provided in Appendix D.
5.4 Testing methods for total bacteria in indoor air are outlined in Appendix E.
5.5 Thermal environment parameters in indoor air are covered in Appendix F.
Appendix A
(Normative Appendix)
Indoor Air Sampling Technical Guidelines
1. Scope
This guideline provides guidance on selecting sampling points, setting sampling height, determining sampling time and frequency, choosing appropriate sampling methods, and implementing quality assurance measures. It serves as a reference for air sampling procedures under the "Indoor Air Quality Standard" and applies to all specified pollutants.
2. Sampling Point Selection
2.1 The number of sampling points depends on the size of the room and site conditions. Rooms under 50 m² should have 1–3 points; 50–100 m² should have 3–5 points; and rooms over 100 m² should have at least 5 points, distributed diagonally or evenly.
2.2 Sampling points should avoid vents and be at least 0.5 meters away from walls.
2.3 Sampling height should be between 0.5 m and 1.5 m, consistent with the human breathing zone.
3. Sampling Time and Frequency
Doors and windows must be closed for at least 4 hours before sampling. For average daily concentrations, continuous sampling for 18 hours is required. For 8-hour averages, 6 hours of sampling is needed, and for 1-hour averages, 45 minutes of sampling is sufficient.
4. Sampling Methods and Equipment
Choose appropriate sampling methods and instruments based on the type of contaminant. The noise level of the sampler should not exceed 50 dB. Specific methods should follow the procedures outlined in each pollutant's testing protocol.
5. Quality Assurance Measures
5.1 Ensure the sampling system is airtight before use to prevent gas leakage.
5.2 Calibrate the flow rate using a soap film meter before and after sampling, ensuring an error margin of no more than 5%.
5.3 Conduct blank tests by leaving two sampling tubes unexposed during a batch of sampling. If the results exceed the control range, the entire batch is invalid.
5.4 Inspect and calibrate instruments according to manufacturer instructions before use.
5.5 Convert sample volume to standard conditions using the equation: V₀ = V × (T₀/P₀) × (P/T), where T₀ = 273 K, P₀ = 101.3 kPa.
5.6 Parallel samples should not differ by more than 20% from the average value.
6. Records and Reports
Keep detailed records of site conditions, pollution sources, date, time, location, atmospheric pressure, temperature, humidity, wind speed, and the sampler’s signature. Submit these along with the samples to the laboratory for analysis.
Appendix B
(Normative Appendix)
Test Method for Various Parameters in Indoor Air
Contaminant testing methods include:
1. Sulfur dioxide: Formaldehyde absorption - Pararosaniline hydrochloride spectrophotometry (GB/T 16128-1995)
2. Nitrogen dioxide: Modified Saltzman method (GB/T 12372-90, GB/T 15435-1995)
3. Carbon monoxide: Non-dispersive infrared method (GB 9801-88, GB/T 18204.23-2000)
4. Carbon dioxide: Infrared gas analysis, gas chromatography, or capacity titration (GB/T 18204.24-2000)
5. Ammonia: Indophenol blue spectrophotometry, Nessler reagent, or ion selective electrode (GB/T 14669-93, GB/T 14679-93, GB/T 18204.25-2000)
6. Ozone: UV spectrophotometry or indigo-sodium disulfonate method (GB/T 15438-1995, GB/T 18204.27-2000)
7. Formaldehyde: AHMT spectrophotometry, phenol reagent, or acetylacetone method (GB/T 15516-95, GB/T 16129-95, GB/T 18204.26-2000)
8. Benzene: Gas chromatography (GB 11737-89, Appendix C)
9. Toluene and Xylene: Gas chromatography (GB 14677-93)
10. Benzo[a]pyrene: High-performance liquid chromatography (GB/T 15439-1995)
11. Respirable Particles: Impact-type weighing method (GB/T 17095-1997)
12. Total Volatile Organic Compounds (TVOC): Gas chromatography (Appendix D)
13. Bacterial Count: Impact method (Appendix E)
14. Thermal Environment Parameters: Temperature, humidity, and airflow (Appendix F)
15. New Air Volume: Tracer gas method (GB/T 18204.18-2000)
16. Radon: Scintillation vial method or standard measurement (GB/T 16147-1995, GB/T 14582-93)
*Note: Method (1) is the arbitration method.*
Ultra High Pressure Cleaning Hose
The Ultra High Pressure Cleaning Hose is a top-of-the-line product designed specifically for heavy-duty cleaning applications. This hose is capable of handling pressures up to 40,000 PSI, making it suitable for use in tough industrial cleaning environments. It is made from high-quality materials that provide exceptional durability and resistance to wear and tear.
Ultra High Pressure Cleaning Hose,Resin Hose,Water Jet Cleaning Hose,Ship High Pressure Cleaning Hose
Luohe Letone Hydraulic Technology Co., Ltd , https://www.litonghose.com