1. What is UV Dose?

UV dose is the product of UV intensity and exposure time, measured in millijoules per square centimeter (mJ/cm²). It's a critical parameter in UV disinfection processes, determining the effectiveness of UV treatment against microorganisms.

2. How Does the Calculator Work?

The calculator uses the UV dose equation:

Where:

• \( Intensity \) — UV light intensity in milliwatts per square centimeter (mW/cm²)
• \( Time \) — Exposure duration in seconds

Explanation: The equation accounts for both the strength of the UV source and how long the exposure lasts.

3. Importance of UV Dose Calculation

Details: Proper UV dose calculation is essential for effective disinfection. Different microorganisms require different UV doses for inactivation. Under-dosing may lead to inadequate disinfection, while over-dosing wastes energy and may damage materials.

4. Using the Calculator

Tips: Enter UV intensity in mW/cm² and exposure time in seconds. Both values must be positive numbers. Typical UV intensity for germicidal lamps ranges from 0.1 to 10 mW/cm².

5. Frequently Asked Questions (FAQ)

Q1: What is a typical UV dose for water disinfection?
A: For drinking water, 40 mJ/cm² is commonly used to achieve 4-log (99.99%) inactivation of most bacteria and viruses.

Q2: How does UV dose relate to disinfection effectiveness?
A: Higher UV doses generally provide greater microbial inactivation, though different organisms have varying sensitivity to UV.

Q3: What factors affect UV dose besides intensity and time?
A: Water quality (turbidity, absorbance), lamp aging, temperature, and reactor design can all affect the delivered UV dose.

Q4: What's the difference between mW/cm² and mJ/cm²?
A: mW/cm² measures irradiance (power per area), while mJ/cm² measures fluence (energy per area). 1 mJ/cm² = 1 mW/cm² × 1 second.

Q5: Can this calculator be used for UV curing applications?
A: Yes, the same principle applies, though curing typically uses much higher doses (hundreds to thousands of mJ/cm²).