ISA Certified Control Systems Technician
(CCST) Level II Practice Exam Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A Instant
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1. Which type of signal is typically transmitted over a 4–20 mA current loop?
A. Digital voltage
B. Pulse-width modulated
C. Analog current
D. Frequency
Rationale: A 4–20 mA loop is used to transmit analog process variables from
field devices to controllers.
2. What is the primary function of a PID controller?
A. Measure process variables
B. Convert digital signals to analog
C. Maintain a process variable at a setpoint
D. Supply power to actuators
Rationale: PID controllers adjust outputs to maintain a process variable at a
desired setpoint using proportional, integral, and derivative control.
3. Which device is used to detect level in a tank without physical contact?
A. Float switch
, B. Capacitance probe
C. Ultrasonic sensor
D. Paddle switch
Rationale: Ultrasonic sensors measure distance to the liquid surface using sound
waves without contact.
4. What is the purpose of a HART protocol?
A. Convert digital signals to analog
B. Enable digital communication over analog 4–20 mA loops
C. Provide wireless data only
D. Amplify process signals
Rationale: HART allows digital communication to coexist with analog 4–20 mA
signals for diagnostics and configuration.
5. What does “deadband” in a controller refer to?
A. Maximum output limit
B. Range of input change that produces no output change
C. Time delay in response
D. Derivative gain
Rationale: Deadband prevents minor fluctuations from causing unnecessary
control output changes.
6. Which type of valve actuator uses an electric motor to position the valve?
A. Pneumatic
B. Electric
C. Hydraulic
D. Manual
Rationale: Electric actuators use motors for precise valve positioning.
7. A transmitter has a span of 0–100 psi and outputs 4–20 mA. What is the
current output for 50 psi?
A. 10 mA
B. 12 mA
, C. 12 mA
D. 14 mA
Rationale: 50 psi is halfway through the 0–100 psi span. Halfway in 4–20 mA
loop = 12 mA.
8. Which signal type is least affected by electrical noise over long distances?
A. 0–10 V
B. Thermocouple voltage
C. 4–20 mA current
D. Potentiometer voltage
Rationale: Current loops are less susceptible to noise because current remains
constant even if resistance changes.
9. What is the main purpose of a safety instrumented system (SIS)?
A. Optimize process efficiency
B. Provide operator alarms
C. Reduce risk by taking automated action on hazardous conditions
D. Record process data
Rationale: SIS is designed to prevent hazardous events by automatically shutting
down or controlling equipment.
10.Which type of controller output is suitable for a valve with a 3–15 psi
pneumatic signal?
A. 4–20 mA
B. 0–10 V
C. 3–15 psi pneumatic
D. Digital ON/OFF
Rationale: The output must match the valve’s required signal range.
11.Which type of flow meter uses differential pressure to determine flow?
A. Ultrasonic
B. Orifice plate
(CCST) Level II Practice Exam Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A Instant
Download Pdf
1. Which type of signal is typically transmitted over a 4–20 mA current loop?
A. Digital voltage
B. Pulse-width modulated
C. Analog current
D. Frequency
Rationale: A 4–20 mA loop is used to transmit analog process variables from
field devices to controllers.
2. What is the primary function of a PID controller?
A. Measure process variables
B. Convert digital signals to analog
C. Maintain a process variable at a setpoint
D. Supply power to actuators
Rationale: PID controllers adjust outputs to maintain a process variable at a
desired setpoint using proportional, integral, and derivative control.
3. Which device is used to detect level in a tank without physical contact?
A. Float switch
, B. Capacitance probe
C. Ultrasonic sensor
D. Paddle switch
Rationale: Ultrasonic sensors measure distance to the liquid surface using sound
waves without contact.
4. What is the purpose of a HART protocol?
A. Convert digital signals to analog
B. Enable digital communication over analog 4–20 mA loops
C. Provide wireless data only
D. Amplify process signals
Rationale: HART allows digital communication to coexist with analog 4–20 mA
signals for diagnostics and configuration.
5. What does “deadband” in a controller refer to?
A. Maximum output limit
B. Range of input change that produces no output change
C. Time delay in response
D. Derivative gain
Rationale: Deadband prevents minor fluctuations from causing unnecessary
control output changes.
6. Which type of valve actuator uses an electric motor to position the valve?
A. Pneumatic
B. Electric
C. Hydraulic
D. Manual
Rationale: Electric actuators use motors for precise valve positioning.
7. A transmitter has a span of 0–100 psi and outputs 4–20 mA. What is the
current output for 50 psi?
A. 10 mA
B. 12 mA
, C. 12 mA
D. 14 mA
Rationale: 50 psi is halfway through the 0–100 psi span. Halfway in 4–20 mA
loop = 12 mA.
8. Which signal type is least affected by electrical noise over long distances?
A. 0–10 V
B. Thermocouple voltage
C. 4–20 mA current
D. Potentiometer voltage
Rationale: Current loops are less susceptible to noise because current remains
constant even if resistance changes.
9. What is the main purpose of a safety instrumented system (SIS)?
A. Optimize process efficiency
B. Provide operator alarms
C. Reduce risk by taking automated action on hazardous conditions
D. Record process data
Rationale: SIS is designed to prevent hazardous events by automatically shutting
down or controlling equipment.
10.Which type of controller output is suitable for a valve with a 3–15 psi
pneumatic signal?
A. 4–20 mA
B. 0–10 V
C. 3–15 psi pneumatic
D. Digital ON/OFF
Rationale: The output must match the valve’s required signal range.
11.Which type of flow meter uses differential pressure to determine flow?
A. Ultrasonic
B. Orifice plate
