Paschen's Law Gas Calculator

Paschen's Law:

\[ V = \frac{B p d}{\ln(A p d + 1)} \]

Breakdown Voltage (V):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Paschen's Law?

Paschen's Law describes the breakdown voltage necessary to initiate an electrical discharge in a gas between two electrodes. It shows that the breakdown voltage depends on the product of gas pressure and electrode distance.

2. How Does the Calculator Work?

The calculator uses Paschen's Law equation:

\[ V = \frac{B p d}{\ln(A p d + 1)} \]

Where:

\( V \) — Breakdown voltage (V)
\( p \) — Gas pressure (torr)
\( d \) — Distance between electrodes (cm)
\( A \) — Constant related to gas properties
\( B \) — Constant related to gas properties

Explanation: The equation shows that breakdown voltage depends on the product of pressure and distance, with constants A and B specific to the gas type.

3. Importance of Paschen's Law

Details: Paschen's Law is crucial for designing electrical equipment operating in gaseous environments, predicting insulation breakdown, and understanding gas discharge phenomena in various applications.

4. Using the Calculator

Tips: Enter pressure in torr, distance in cm, and appropriate constants A and B for the specific gas. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for constants A and B?
A: Constants vary by gas. For air: A ≈ 15 cm⁻¹·torr⁻¹, B ≈ 365 V·cm⁻¹·torr⁻¹. Consult gas-specific tables for accurate values.

Q2: Does Paschen's Law apply to all gases?
A: Yes, but with different A and B constants for each gas. The law describes the general relationship between breakdown voltage, pressure, and distance.

Q3: What is the Paschen minimum?
A: The minimum breakdown voltage occurs at a specific p·d product. Below and above this minimum, higher voltages are required for breakdown.

Q4: Are there limitations to Paschen's Law?
A: The law assumes uniform electric fields and may not accurately predict breakdown in non-uniform fields or at very high pressures/distances.

Q5: How is Paschen's Law used in practical applications?
A: It's used in designing high-voltage equipment, vacuum systems, gas-filled tubes, and predicting insulation performance in various atmospheric conditions.