What instrument is used to measure pressures around the 10⁻⁶ torr range__________________?
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Answer: D. ionisastion gauge
Explanation
Ionization gauges operate by ionizing gas molecules inside the vacuum chamber and measuring the resulting electrical current. This specific electrical current correlates directly with extremely low gas densities found in high vacuum environments down to 10⁻⁶ torr. Other mechanical gauges lack the necessary sensitivity to detect the minute gas pressures present in deep vacuum systems. A torr is a unit of pressure defined as exactly 1/760 of a standard atmosphere or one millimeter of mercury. High vacuum research and semiconductor manufacturing frequently require specialized instrumentation capable of measuring extremely rarefied gaseous environments. Hot cathode ionization gauges utilize a heated filament to emit electrons that collide with and ionize residual gas molecules.
Bourdon tube pressure gauges utilize elastic metal tubes that straighten under pressure, making them completely useless for measuring deep vacuums. Pirani gauges measure thermal conductivity of gases and are typically limited to medium vacuum ranges rather than extreme high vacuums. McLeod gauges compress a known volume of gas to measure pressure, but they are cumbersome and largely unsuitable for continuous electronic monitoring.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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