Features of UV-Filtering Quartz Tubes

UV-filtering quartz tubes are specially treated quartz glass tubes designed to selectively block specific ultraviolet (UV) wavelengths while maintaining high transparency in the visible and infrared ranges. Their key characteristics include:

1. UV Blocking Performance

Cut-off Wavelength:

• Common models block UV below 280 nm (UV-C) ή 320 nm (UV-B), allowing transmission primarily above 320 nm (UV-A, visible light, and infrared).
• Some high-purity quartz (e.g., JGS1) naturally transmits UV down to 185 nm, requiring doping with elements such as titanium (Ti) ή cerium (Ce) to achieve UV cut-off.

Filtering Efficiency:

• For UV-C (200–280 nm), filtering efficiency can reach >99% in Ti-doped quartz tubes.

2. Optical Properties

Transmittance:

• Visible light range (400–700 nm): ≥90%
• Infrared range (700–2500 nm): ≥85%
• Steep UV cut-off edge: For example, transmittance may jump from 0% at 280 nm to 80% at 300 nm.

Refractive Index: 1.458 (@589 nm), same as standard quartz glass.

3. Material and Structure

Base Material:

• High-purity synthetic quartz (SiO₂ ≥ 99.99%) with low hydroxyl content (<5 ppm) to minimize IR absorption.

Doping Elements:

• Titanium (Ti), Cerium (Ce), Iron (Fe), etc., used to adjust UV absorption peaks.

Φυσικές ιδιότητες:

• Density: 2.2 g/cm³
• Mohs hardness: 7
• Bending strength: ≥50 MPa
• Thermal expansion coefficient: 5.5×10⁻⁷/°C (20–300 °C)
• Excellent thermal shock resistance

4. Environmental Durability

High-Temperature Resistance:

• Continuous use up to 1100 °C, short-term up to 1300 °C (note: doping may slightly reduce thermal tolerance).

Corrosion Resistance:

• Resistant to acids (except HF) and steam; alkaline environments (e.g., KOH) may corrode the surface.

Radiation Stability:

• Withstands γ-ray and X-ray exposure without darkening; Ce-doped quartz shows superior radiation resistance.

5. Application Scenarios

UV Shielding:

• Protective outer sleeves for germicidal lamps (block harmful UV-C, allow useful UV-B/UVA).
• Semiconductor photolithography (precise control of exposure wavelength).

Optical Devices:

• Spectrometer windows, laser tube casings (designed for specific light bands).

Special Lighting:

• Aquarium lighting (UV protection for aquatic life).

6. Precautions

• Avoid Mechanical Impact: Quartz is brittle—shock protection is essential during installation.
• Cleaning: Use alcohol or deionized water; avoid hard objects.
• Service Life: Long-term exposure to heat and UV may cause slow degradation due to dopant migration.

Comparison: UV-Filtering Quartz Tube vs. Standard Quartz Tube

Need a specific model? Please provide the required UV cut-off wavelength and transmission curve for accurate matching.