1. What is Paschen's Law?

Paschen's Law describes the breakdown voltage necessary to initiate an electric discharge between two electrodes in a gas as a function of pressure and gap distance. It's fundamental in designing high-voltage equipment and understanding gas insulation properties.

2. How Does the Calculator Work?

The calculator uses Paschen's Law equation:

Where:

• \( V \) — Breakdown voltage (V)
• \( pd \) — Pressure × distance product (Torr·cm)
• \( a \) — First constant (typically 24.4 for air)
• \( b \) — Second constant (typically 6.29 for air)

Explanation: The equation shows that breakdown voltage depends on both the gas pressure and the distance between electrodes.

3. Importance of Breakdown Voltage Calculation

Details: Accurate breakdown voltage estimation is crucial for designing electrical insulation systems, high-voltage equipment, and preventing unwanted electrical discharges.

4. Using the Calculator

Tips: Enter the pressure-distance product (pd) in Torr·cm and the constants a and b. Default values are provided for air (a=24.4, b=6.29).

5. Frequently Asked Questions (FAQ)

Q1: What is the Paschen minimum?
A: The minimum breakdown voltage that occurs at a specific pd product, below which breakdown voltage increases with decreasing pressure.

Q2: What gases does this apply to?
A: Paschen's Law applies to all gases, though the constants a and b vary depending on the gas composition.

Q3: What are typical values for a and b?
A: For air: a≈24.4, b≈6.29. For other gases, different values must be used (e.g., SF6 has different constants).

Q4: What are the limitations of Paschen's Law?
A: It assumes uniform electric fields, constant temperature, and doesn't account for electrode surface effects or time-varying fields.

Q5: How does humidity affect breakdown voltage?
A: Increased humidity generally increases breakdown voltage in air, though Paschen's Law in basic form doesn't account for this.