Nitrogen Dioxide (NO₂)
Product Overview
Nitrogen dioxide (NO₂) is a critical calibration gas for Continuous emission monitoring systems (CEMS), ambient air monitors, and stack testing equipment. Accurate NO₂ measurements are essential for regulatory compliance under EPA 40 CFR Part 60, Part 75, and corresponding international standards .
The global NO₂ calibration gas market is driven by increasingly stringent environmental regulations worldwide. According to industry data, the electronic specialty gas market reached $4.64 billion in 2025, with calibration gases representing a growing segment .
Technical Specifications
| Parameter | EPA Protocol Grade | Research Grade |
|---|---|---|
| Concentration | Custom (10-500 ppm) | Custom (ppm to % levels) |
| Balance Gas | Nitrogen or air | Nitrogen or air |
| Uncertainty | ±2% relative | ±1-5% depending on concentration |
| Traceability | NIST-traceable | NIST or national standard traceable |
| Certificate | EPA protocol certificate | Certificate of Analysis |
Applications
Environmental Monitoring
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CEMS calibration for stationary source emissions (EPA Method 7E)
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Ambient air quality monitor calibration
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Stack testing for regulatory compliance
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Emissions trading program verification
Industrial Process Control
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Chemical process optimization monitoring
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Nitric acid plant emissions control
Research & Development
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Catalyst testing for NOx reduction (SCR, SNCR)
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Atmospheric chemistry studies
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Material compatibility testing
Regulatory Framework
NO₂ calibration gases are used for compliance with:
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US EPA: 40 CFR Part 60, Part 75, Performance Specifications
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EU: Industrial Emissions Directive, EN 14181
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China: HJ 75, HJ 76 CEMS specifications
Certified calibration standards must be traceable to national metrology institutes with documented uncertainty budgets .
Safety & Handling
NO₂ is a toxic, corrosive, and oxidizing gas:
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Highly reactive with moisture (forms nitric acid)
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Requires stainless steel or passivated cylinders
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Store in gas cabinets with continuous monitoring
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Dedicated toxic gas detection systems required
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Personal protective equipment essential for handling
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Emergency response procedures for potential releases
Cylinder Preparation
NO₂ requires specialized cylinder treatments:
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Passivated internal surfaces to prevent decomposition
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Stainless steel diaphragm valves
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Concentration verification throughout shelf life
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Stability documentation for regulatory acceptance
Quality Assurance
Chengdu Hongjin Chemical Co., Ltd. provides nitrogen dioxide calibration gases with:
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EPA protocol certificates for regulatory compliance
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NIST-traceable calibration standards
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Certificate of Analysis with documented uncertainty
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Specialized cylinder handling for reactive gases
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Technical support for CEMS and stack testing applications
References:
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US EPA 40 CFR Part 60, Part 75
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EPA Method 7E for NOx Emissions
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TECHCET Electronic Specialty Gases Market Report, 2026