CIRO TEST QUESTIONS AND
ANSWERS 2025/2026
What is the lowest level in PPM at which ammonia is generally detectable
A. 4 PPM
B. 5 PPM
C. 2 PPM
D. 8 PPM - ANSWERS
Which gas is suitable for leak checking a modified pipe section of an ammonia system
A. Sulfur dioxide
B. R-22
C. Dry nitrogen
D. R-414b - ANSWERS
Which of these is true for a shell and tube condenser
A. Water evaporates in the tubes
B. Refrigerant flows through the tubes
C. Water flows through the shell
D. Refrigerant flows around the tubes - ANSWERS
Which of these are factors in determining wet bulb temperature
A. Moisture content and temperature of ambient air
B. Ambient air temperature and discharge temperature
C. Seasonal humidity
D. Discharge temperature and suction pressure - ANSWERS
In a facility served only by flooded units, under what conditions will the indicated liquid
level run higher in the high pressure receiver when all evaporators are operating
normally and not in defrost
A. When the refrigerant hangs up in the condenser
B. When the plant is running at maximum load conditions
C. When the plant is running at minimum load conditions
D. The level does not shift in the high pressure receiver - ANSWERS
Which of these require a dual relief valve assembly on pressure vessels
A. A volume of one cubic foot or more
B. It is recommended but never required
C. A volume of 10 cubic feet or more
D. A volume of 100 cubic feet or more - ANSWERS
Which of these are used as measurements for determining presence of non-
condensables?
, A. Compressor inlet pressure and temperature
B. Compressor discharge pressure and temperature
C. Condenser water temperature and inlet header pressure
D. Condenser refrigerant outlet temperature and pressure - ANSWERS
How is capacity control achieved on a single speed screw compressor
A. By moving the slide valve or slide piston
B. By throttling the bypass valve
C. By moving the guide vanes
D. Screw compressors do not have capacity control - ANSWERS
A 100 ton evaporator is operating at -40deg F with the condenser operating at 95deg F.
Considering energy consumption only, which of these arrangements would have the
lowest energy use when operating?
A. Single stage centrifugal
B. Single stage piston machines
C. Single stage screw machines
D. Two stage system - ANSWERS
The oil draining procedure an operator performs
A. Is not necessary because oil draining is automatic
B. Is not necessary because oil stays miscible in anhydrous ammonia
C. Is really not necessary with todays lubricants
D. May be the most dangerous task an operator performs - ANSWERS
Which of these fan coil units would use the FEWEST fins per inch
A. Depends on refrigerant
B. +40deg F air conditions coil
C. +20deg F cold storage coil
D. -40deg F blast freezer coil - ANSWERS
Which of these forms of protective eye wear are recommended when handling
refrigerants
A. Safety glasses and full face respirator
B. Full face respirator
C. Chemical goggles
D. Face shield and safety glasses - ANSWERS
A faulty pressure gauge
A. Is too expensive to replace
B. Has no effect on the shift operator
C. Has no credibility
D. Has no effect on the engine room log - ANSWERS
In preparation for working on electrical circuits, the circuitry should be de-engergized
and de-energization should be confirmed by
ANSWERS 2025/2026
What is the lowest level in PPM at which ammonia is generally detectable
A. 4 PPM
B. 5 PPM
C. 2 PPM
D. 8 PPM - ANSWERS
Which gas is suitable for leak checking a modified pipe section of an ammonia system
A. Sulfur dioxide
B. R-22
C. Dry nitrogen
D. R-414b - ANSWERS
Which of these is true for a shell and tube condenser
A. Water evaporates in the tubes
B. Refrigerant flows through the tubes
C. Water flows through the shell
D. Refrigerant flows around the tubes - ANSWERS
Which of these are factors in determining wet bulb temperature
A. Moisture content and temperature of ambient air
B. Ambient air temperature and discharge temperature
C. Seasonal humidity
D. Discharge temperature and suction pressure - ANSWERS
In a facility served only by flooded units, under what conditions will the indicated liquid
level run higher in the high pressure receiver when all evaporators are operating
normally and not in defrost
A. When the refrigerant hangs up in the condenser
B. When the plant is running at maximum load conditions
C. When the plant is running at minimum load conditions
D. The level does not shift in the high pressure receiver - ANSWERS
Which of these require a dual relief valve assembly on pressure vessels
A. A volume of one cubic foot or more
B. It is recommended but never required
C. A volume of 10 cubic feet or more
D. A volume of 100 cubic feet or more - ANSWERS
Which of these are used as measurements for determining presence of non-
condensables?
, A. Compressor inlet pressure and temperature
B. Compressor discharge pressure and temperature
C. Condenser water temperature and inlet header pressure
D. Condenser refrigerant outlet temperature and pressure - ANSWERS
How is capacity control achieved on a single speed screw compressor
A. By moving the slide valve or slide piston
B. By throttling the bypass valve
C. By moving the guide vanes
D. Screw compressors do not have capacity control - ANSWERS
A 100 ton evaporator is operating at -40deg F with the condenser operating at 95deg F.
Considering energy consumption only, which of these arrangements would have the
lowest energy use when operating?
A. Single stage centrifugal
B. Single stage piston machines
C. Single stage screw machines
D. Two stage system - ANSWERS
The oil draining procedure an operator performs
A. Is not necessary because oil draining is automatic
B. Is not necessary because oil stays miscible in anhydrous ammonia
C. Is really not necessary with todays lubricants
D. May be the most dangerous task an operator performs - ANSWERS
Which of these fan coil units would use the FEWEST fins per inch
A. Depends on refrigerant
B. +40deg F air conditions coil
C. +20deg F cold storage coil
D. -40deg F blast freezer coil - ANSWERS
Which of these forms of protective eye wear are recommended when handling
refrigerants
A. Safety glasses and full face respirator
B. Full face respirator
C. Chemical goggles
D. Face shield and safety glasses - ANSWERS
A faulty pressure gauge
A. Is too expensive to replace
B. Has no effect on the shift operator
C. Has no credibility
D. Has no effect on the engine room log - ANSWERS
In preparation for working on electrical circuits, the circuitry should be de-engergized
and de-energization should be confirmed by
