PCI ISA (Latest) Questions & Answers 2024
| 100% Correct Verified Study Guide
Question 1: Which electrical parameter must be verified within ±1 % accuracy during an
ISA-5.1-2020 instrument loop check?
A) Loop resistance
B) Supply pressure
C) 4-20 mA output value
D) Cable tray temperature
Correct Answer: C) 4-20 mA output value
Explanation: ISA-5.1-2020 mandates that the standard 4-20 mA analogue signal be verified to ±1
% of span to ensure that the DCS or PLC receives a measurement within the accuracy class of the
transmitter; resistance or pressure checks are secondary and temperature is not part of the
loop-accuracy clause.
Question 2: In a PCI-ISA safety instrumented function (SIF), what is the minimum required
proof-test coverage for a Type B sensor with an SIL 3 target?
A) 50 %
B) 70 %
C) 90 %
, D) 99 %
Correct Answer: C) 90 %
Explanation: Per ISA-TR84.00.03-2019 Table 5.1, a Type B field device used in an SIL 3 loop must
demonstrate ≥90 % proof-test coverage so that the undetected dangerous-failure fraction is low
enough to meet the PFDavg required for SIL 3.
Question 3: Which cable shield grounding scheme does ISA-RP60.6-2021 recommend for
high-speed PCI data-acquisition cards to minimize EMI?
A) Ground at both ends
B) Ground at DCS end only
C) Capacitive coupling at one end
D) No shield ground
Correct Answer: B) Ground at DCS end only
Explanation: RP60.6-2021 advises single-point (DCS-end) shield grounding for high-frequency I/O
cards to prevent ground-loop currents that would raise noise floor; double-ended grounding is
reserved for low-frequency, noise-immune power circuits.
Question 4: During ISA-18.2 alarm-management rationalization, which risk matrix axis combines
consequence and likelihood to set the alarm priority for a PCI pressure transmitter?
A) Severity vs. frequency
B) Cost vs. downtime
C) SIL vs. availability
| 100% Correct Verified Study Guide
Question 1: Which electrical parameter must be verified within ±1 % accuracy during an
ISA-5.1-2020 instrument loop check?
A) Loop resistance
B) Supply pressure
C) 4-20 mA output value
D) Cable tray temperature
Correct Answer: C) 4-20 mA output value
Explanation: ISA-5.1-2020 mandates that the standard 4-20 mA analogue signal be verified to ±1
% of span to ensure that the DCS or PLC receives a measurement within the accuracy class of the
transmitter; resistance or pressure checks are secondary and temperature is not part of the
loop-accuracy clause.
Question 2: In a PCI-ISA safety instrumented function (SIF), what is the minimum required
proof-test coverage for a Type B sensor with an SIL 3 target?
A) 50 %
B) 70 %
C) 90 %
, D) 99 %
Correct Answer: C) 90 %
Explanation: Per ISA-TR84.00.03-2019 Table 5.1, a Type B field device used in an SIL 3 loop must
demonstrate ≥90 % proof-test coverage so that the undetected dangerous-failure fraction is low
enough to meet the PFDavg required for SIL 3.
Question 3: Which cable shield grounding scheme does ISA-RP60.6-2021 recommend for
high-speed PCI data-acquisition cards to minimize EMI?
A) Ground at both ends
B) Ground at DCS end only
C) Capacitive coupling at one end
D) No shield ground
Correct Answer: B) Ground at DCS end only
Explanation: RP60.6-2021 advises single-point (DCS-end) shield grounding for high-frequency I/O
cards to prevent ground-loop currents that would raise noise floor; double-ended grounding is
reserved for low-frequency, noise-immune power circuits.
Question 4: During ISA-18.2 alarm-management rationalization, which risk matrix axis combines
consequence and likelihood to set the alarm priority for a PCI pressure transmitter?
A) Severity vs. frequency
B) Cost vs. downtime
C) SIL vs. availability
