The ionization gauge an instrument used for the measurement ofa)Very ...
The ionization gauge is a special type of instrument used for measuring very low pressures in the range 10−10 to 1 mbar.
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The ionization gauge an instrument used for the measurement ofa)Very ...
The ionization gauge is an instrument used for the measurement of very low pressure. It operates on the principle of ionization of gas molecules in a vacuum to measure the pressure.
Explanation:
1. Principle of operation:
The ionization gauge consists of a filament wire and an anode, both enclosed in a glass envelope. When an electric current is passed through the filament, it heats up and emits electrons. These electrons collide with gas molecules in the vacuum, causing ionization. The positively charged ions are attracted towards the negatively charged anode, where they create a measurable electric current.
2. Measurement of pressure:
The ionization gauge measures pressure indirectly by measuring the ion current produced. As the pressure decreases, the number of gas molecules available for ionization decreases, resulting in a decrease in the ion current. By calibrating the gauge with known pressures, the ion current can be correlated to the pressure.
3. Operating range:
The ionization gauge is particularly suited for measuring very low pressures, typically in the range of 10^-3 to 10^-10 torr. It is highly sensitive and can accurately measure pressures in the ultra-high vacuum range.
4. Advantages:
- High sensitivity: The ionization gauge can detect very small changes in pressure due to its high sensitivity.
- Wide measurement range: It can measure pressures over a wide range, from very low pressures to atmospheric pressures.
- Fast response time: The ionization gauge has a fast response time, allowing for real-time pressure monitoring.
5. Limitations:
- Contamination: The gauge is sensitive to contamination, as the presence of foreign particles or gases can affect the ionization process and result in inaccurate measurements.
- Sensitivity to gas composition: The ionization gauge is optimized for measuring the pressure of certain gases, and its accuracy may vary with different gas compositions.
In conclusion, the ionization gauge is an instrument used for measuring very low pressure. It operates by ionizing gas molecules in a vacuum and measuring the resulting ion current. Its high sensitivity and wide measurement range make it suitable for various applications in vacuum technology.