Question 1 — Pressure Units

Which of the following correctly states the relationship between pressure units at standard sea-level atmospheric pressure?

• A. 1 atm = 1013 Torr = 760 mbar = 101,325 Pa
• B. 1 atm ≈ 1013 mbar ≈ 760 Torr ≈ 101,325 Pa
• C. 1 atm = 950 mbar = 760 Torr = 101,325 Pa
• D. 1 atm = 1013 mbar = 1013 Torr = 1013 Pa

Question 2 — Component Naming

In the R1-A component naming convention, what does the "G" in "R1-G-CH" indicate?

• A. Gas
• B. Gauge
• C. Gate
• D. General

Question 3 — State Identification from Readings

On the R1-A rig, the following conditions are observed: R1-V-VENT is closed, R1-V-ISO is open, R1-P-RP is running, R1-G-CH reads 85 mbar and dropping, R1-G-BX reads 950 mbar. What state is the system in?

• A. VENTED
• B. ISOLATED
• C. ROUGHING
• D. CONTROLLED VENT

Question 4 — State Identification

On the R1-A rig, R1-V-VENT is closed, R1-V-ISO is closed, R1-P-RP is off, R1-G-CH reads 3 mbar, R1-G-BX reads 950 mbar. What state is the system in?

• A. VENTED
• B. ISOLATED
• C. ROUGHING
• D. CONTROLLED VENT

Question 5 — Pressure Type Application

A gauge in a lab at sea level reads a gauge pressure of -1013 mbar. A gauge on the same type of system at Selkirk College reads a gauge pressure of -950 mbar. Both gauges show the maximum negative reading possible at their respective locations. What does this indicate about the absolute pressure in both systems?

• A. Both systems are at approximately 0 mbar absolute (perfect vacuum) — each gauge reads the full negative value of its local atmospheric pressure
• B. The systems are at different absolute pressures because the gauge readings differ
• C. Both systems are at 950 mbar absolute
• D. Both systems are at 1013 mbar absolute

Question 6 — Pressure Range Classification

A chamber gauge reads 5 × 10^-2 mbar. Which vacuum pressure range does this fall into?

• A. Rough vacuum (atmospheric to 1 mbar)
• B. Medium vacuum (1 mbar to 10^-3 mbar)
• C. High vacuum (10^-3 to 10^-7 mbar)
• D. Ultra-high vacuum (below 10^-7 mbar)

Question 7 — Gas Flow Path Tracing

During a controlled vent on the R1-A, atmospheric air enters the chamber. The correct flow path for the incoming air is:

• A. ATM → R1-FLT-VENT → R1-L-VENT → R1-V-VENT → R1-CH
• B. ATM → R1-V-VENT → R1-FLT-VENT → R1-L-VENT → R1-CH
• C. ATM → R1-V-ISO → R1-L-FL → R1-P-RP → R1-CH
• D. ATM → R1-L-EXH → R1-FLT-EXH → R1-P-RP → R1-CH

Question 8 — Component Function

The R1-A rig has been pumped down to 1 mbar. The isolation valve (R1-V-ISO) is now closed, sealing the chamber. Which component is observed to determine whether the chamber is holding vacuum or if there is a problem?

• A. R1-G-BX (barometric reference)
• B. R1-G-CH (chamber gauge)
• C. R1-P-RP (roughing pump)
• D. R1-FLT-EXH (exhaust filter)

Question 9 — Valve State Application

During roughing on the R1-A, why must R1-V-VENT remain closed?

• A. To prevent the pump from overheating
• B. To protect the exhaust filter from excessive gas flow
• C. To prevent atmospheric air from entering the chamber while the pump is trying to remove gas
• D. To keep the barometric reference gauge reading stable

Question 10 — Selkirk Atmospheric Application

On the R1-A rig at Selkirk College, the chamber gauge (R1-G-CH) reads 475 mbar and the barometric reference (R1-G-BX) reads 950 mbar. The chamber pressure is 475 mbar below the starting atmospheric value. What does this relationship between the two readings indicate about how much gas remains in the chamber?

• A. Approximately half the original atmospheric gas has been removed — the chamber pressure is halfway between atmosphere and perfect vacuum
• B. About one quarter of the gas has been removed
• C. About three quarters of the gas has been removed
• D. Almost all of the gas has been removed

Question 11 — Schematic Interpretation

On a vacuum system schematic using DIN 28401 symbols, a valve symbol is shown in the closed position. What does this indicate about the gas flow through that section of the system?

• A. Gas is flowing freely through the valve
• B. Gas flow through that section is blocked
• C. The valve is controlling the flow rate
• D. The valve is partially open for throttling

Question 12 — Component Purpose

On the R1-A rig, the exhaust filter (R1-FLT-EXH) is located on the pump exhaust line. What is its primary function?

• A. To filter incoming air before it reaches the chamber
• B. To measure the quality of the pump exhaust
• C. To capture oil mist from the rotary vane pump before it enters the workspace atmosphere
• D. To regulate the exhaust flow rate

Question 13 — System Transition

The R1-A is currently in the VENTED state (both valves closed, pump off, chamber at ~950 mbar). When the system transitions from VENTED to ROUGHING, which sequence of state changes is observed?

• A. R1-V-VENT opens, then R1-P-RP starts
• B. R1-P-RP starts, then R1-V-ISO opens
• C. R1-V-ISO opens, then R1-V-VENT opens
• D. R1-P-RP starts, then R1-V-VENT opens

Question 14 — Barometric Reference Use

On the R1-A, the chamber gauge (R1-G-CH) reads 948 mbar and the barometric reference (R1-G-BX) reads 950 mbar. All valves are closed and the pump is off. What does this 2 mbar difference most likely indicate?

• A. The system has a significant leak
• B. The vent valve failed to fully close
• C. The chamber is essentially at atmospheric pressure — the small difference is within normal instrument tolerance
• D. The chamber is under vacuum

Question 15 — Rate of Rise Interpretation

The R1-A chamber is isolated at 2 mbar. Over 5 minutes, the pressure rises to 55 mbar. The rate of rise is approximately 10.6 mbar/minute. What does this indicate?

• A. Normal outgassing — this rate is typical for surface desorption
• B. A significant leak — the rate of rise is too fast for normal outgassing alone
• C. The pump has failed
• D. The barometric reference gauge is malfunctioning

Question 16 — Diagnostic Scenario

The R1-A pump has been running for 20 minutes but R1-G-CH still reads 800 mbar. R1-V-ISO is open, R1-V-VENT is closed, and R1-G-BX reads 950 mbar. Which of the following is the most likely explanation?

• A. The chamber is in the ISOLATED state
• B. This is normal — large chambers take time to pump down
• C. The barometric reference gauge is malfunctioning
• D. The pump may not be functioning correctly, or there is a large leak allowing air in at a rate that matches or exceeds the pump's removal rate

Question 17 — Flow Regime Analysis

At the start of a pump-down on the R1-A, the chamber pressure drops rapidly from 950 mbar. As the pressure approaches 1 mbar, the rate of pressure decrease slows significantly. Which statement best explains this change?

• A. The pump is losing power as it warms up
• B. The vent valve is slowly opening
• C. At lower pressures, there are fewer gas molecules to remove per unit time, and the flow regime transitions from viscous to molecular flow where pumping efficiency changes
• D. The chamber gauge becomes less accurate at lower pressures

Question 18 — Comparative Analysis

Two identical vacuum systems are tested — one at sea level (atmospheric pressure 1013 mbar) and one at Selkirk College (atmospheric pressure 950 mbar). Both are pumped down to an absolute pressure of 1 mbar. Which statement is correct?

• A. The sea-level system is at a deeper vacuum because it started at a higher pressure
• B. The Selkirk system is at a deeper vacuum because it had less gas to remove
• C. Both systems are at the same absolute pressure (1 mbar), but the sea-level system had more gas to remove during pump-down
• D. The systems cannot be compared because they are at different elevations

Question 19 — Misconception Analysis

A colleague states: "The roughing pump on our rig can achieve a perfect vacuum if we just leave it running long enough." What is wrong with this statement?

• A. Nothing — given enough time, any pump can reach perfect vacuum
• B. The pump needs to be connected to a turbo pump first
• C. A rotary vane pump has a base pressure limit (approximately 10^-2 mbar) determined by its design, and outgassing from chamber surfaces means pressure never reaches zero regardless of pumping time
• D. The statement is only wrong because the vent valve would need to be open

Question 20 — Diagnostic Decision

On the R1-A, the system has been isolated at 5 mbar after a pump-down. Over 30 minutes, the chamber gauge shows the following readings: 5 min → 5.3 mbar, 10 min → 5.5 mbar, 15 min → 5.7 mbar, 20 min → 5.9 mbar, 25 min → 6.0 mbar, 30 min → 6.1 mbar. The rate of rise is decreasing over time. What does this pattern most likely indicate?

• A. A large leak that is gradually getting worse
• B. A constant leak at a steady rate
• C. Outgassing from chamber surfaces — the decreasing rate is characteristic because surface gas sources deplete over time
• D. The gauge is drifting and needs recalibration

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