Process Instrumentation Basics interview questions

1. A.ratio of maximum to minimum flow a meter reads within stated accuracy, about 4:1 for orifice plates against 20:1 or more for Coriolis
2. B.differential pressure across a sharp-edged restriction where flow is proportional to the square root of DP, so the transmitter needs square-root extraction
3. C.vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run
4. D.platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C

Answer + AI explanation with Pro

1. A.Orifice plate flow measurement
2. B.Coriolis mass flow meter
3. C.Pt100 RTD
4. D.Turndown ratio

Answer + AI explanation with Pro

1. A.Orifice plate flow measurement — platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C
2. B.Orifice plate flow measurement — hydrostatic head between bottom and top taps gives liquid level; a wet leg on the low side requires zero elevation or suppression
3. C.Orifice plate flow measurement — two dissimilar-metal junctions generating a Seebeck voltage proportional to temperature difference; K type (chromel-alumel) covers up to about 1200 °C
4. D.Orifice plate flow measurement — differential pressure across a sharp-edged restriction where flow is proportional to the square root of DP, so the transmitter needs square-root extraction

Answer + AI explanation with Pro

1. A.two dissimilar-metal junctions generating a Seebeck voltage proportional to temperature difference; K type (chromel-alumel) covers up to about 1200 °C
2. B.differential pressure across a sharp-edged restriction where flow is proportional to the square root of DP, so the transmitter needs square-root extraction
3. C.vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run
4. D.ratio of maximum to minimum flow a meter reads within stated accuracy, about 4:1 for orifice plates against 20:1 or more for Coriolis

Answer + AI explanation with Pro

1. A.Thermocouple
2. B.Vortex flow meter
3. C.HART protocol
4. D.Coriolis mass flow meter

Answer + AI explanation with Pro

1. A.Thermocouple — differential pressure across a sharp-edged restriction where flow is proportional to the square root of DP, so the transmitter needs square-root extraction
2. B.Thermocouple — two dissimilar-metal junctions generating a Seebeck voltage proportional to temperature difference; K type (chromel-alumel) covers up to about 1200 °C
3. C.Thermocouple — platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C
4. D.Thermocouple — digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring

Answer + AI explanation with Pro

1. A.platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C
2. B.two dissimilar-metal junctions generating a Seebeck voltage proportional to temperature difference; K type (chromel-alumel) covers up to about 1200 °C
3. C.vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run
4. D.digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring

Answer + AI explanation with Pro

1. A.Pt100 RTD
2. B.HART protocol
3. C.Coriolis mass flow meter
4. D.DP level measurement

Answer + AI explanation with Pro

1. A.Pt100 RTD — platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C
2. B.Pt100 RTD — two dissimilar-metal junctions generating a Seebeck voltage proportional to temperature difference; K type (chromel-alumel) covers up to about 1200 °C
3. C.Pt100 RTD — ratio of maximum to minimum flow a meter reads within stated accuracy, about 4:1 for orifice plates against 20:1 or more for Coriolis
4. D.Pt100 RTD — bluff body sheds vortices at a frequency proportional to velocity, well suited to steam and gas, but reads zero below a minimum Reynolds number

Answer + AI explanation with Pro

1. A.vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run
2. B.standard analogue transmitter output where 4 mA is zero of range; the live zero lets a broken wire (0 mA) be distinguished from a true zero
3. C.differential pressure across a sharp-edged restriction where flow is proportional to the square root of DP, so the transmitter needs square-root extraction
4. D.hydrostatic head between bottom and top taps gives liquid level; a wet leg on the low side requires zero elevation or suppression

Answer + AI explanation with Pro

1. A.Coriolis mass flow meter
2. B.DP level measurement
3. C.HART protocol
4. D.4–20 mA signal

Answer + AI explanation with Pro

1. A.4–20 mA signal — two dissimilar-metal junctions generating a Seebeck voltage proportional to temperature difference; K type (chromel-alumel) covers up to about 1200 °C
2. B.4–20 mA signal — standard analogue transmitter output where 4 mA is zero of range; the live zero lets a broken wire (0 mA) be distinguished from a true zero
3. C.4–20 mA signal — ratio of maximum to minimum flow a meter reads within stated accuracy, about 4:1 for orifice plates against 20:1 or more for Coriolis
4. D.4–20 mA signal — vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run

Answer + AI explanation with Pro

1. A.standard analogue transmitter output where 4 mA is zero of range; the live zero lets a broken wire (0 mA) be distinguished from a true zero
2. B.hydrostatic head between bottom and top taps gives liquid level; a wet leg on the low side requires zero elevation or suppression
3. C.bluff body sheds vortices at a frequency proportional to velocity, well suited to steam and gas, but reads zero below a minimum Reynolds number
4. D.digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring

Answer + AI explanation with Pro

1. A.Coriolis mass flow meter
2. B.Thermocouple
3. C.Orifice plate flow measurement
4. D.DP level measurement

Answer + AI explanation with Pro

1. A.DP level measurement — platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C
2. B.DP level measurement — differential pressure across a sharp-edged restriction where flow is proportional to the square root of DP, so the transmitter needs square-root extraction
3. C.DP level measurement — hydrostatic head between bottom and top taps gives liquid level; a wet leg on the low side requires zero elevation or suppression
4. D.DP level measurement — bluff body sheds vortices at a frequency proportional to velocity, well suited to steam and gas, but reads zero below a minimum Reynolds number

Answer + AI explanation with Pro

1. A.vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run
2. B.standard analogue transmitter output where 4 mA is zero of range; the live zero lets a broken wire (0 mA) be distinguished from a true zero
3. C.digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring
4. D.ratio of maximum to minimum flow a meter reads within stated accuracy, about 4:1 for orifice plates against 20:1 or more for Coriolis

Answer + AI explanation with Pro

1. A.Coriolis mass flow meter
2. B.DP level measurement
3. C.Thermocouple
4. D.Turndown ratio

Answer + AI explanation with Pro

1. A.Coriolis mass flow meter — two dissimilar-metal junctions generating a Seebeck voltage proportional to temperature difference; K type (chromel-alumel) covers up to about 1200 °C
2. B.Coriolis mass flow meter — hydrostatic head between bottom and top taps gives liquid level; a wet leg on the low side requires zero elevation or suppression
3. C.Coriolis mass flow meter — ratio of maximum to minimum flow a meter reads within stated accuracy, about 4:1 for orifice plates against 20:1 or more for Coriolis
4. D.Coriolis mass flow meter — vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run

Answer + AI explanation with Pro

1. A.platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C
2. B.digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring
3. C.vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run
4. D.standard analogue transmitter output where 4 mA is zero of range; the live zero lets a broken wire (0 mA) be distinguished from a true zero

Answer + AI explanation with Pro

1. A.Coriolis mass flow meter
2. B.Vortex flow meter
3. C.Orifice plate flow measurement
4. D.HART protocol

Answer + AI explanation with Pro

1. A.HART protocol — standard analogue transmitter output where 4 mA is zero of range; the live zero lets a broken wire (0 mA) be distinguished from a true zero
2. B.HART protocol — differential pressure across a sharp-edged restriction where flow is proportional to the square root of DP, so the transmitter needs square-root extraction
3. C.HART protocol — platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C
4. D.HART protocol — digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring

Answer + AI explanation with Pro

1. A.ratio of maximum to minimum flow a meter reads within stated accuracy, about 4:1 for orifice plates against 20:1 or more for Coriolis
2. B.standard analogue transmitter output where 4 mA is zero of range; the live zero lets a broken wire (0 mA) be distinguished from a true zero
3. C.digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring
4. D.platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C

Answer + AI explanation with Pro

1. A.4–20 mA signal
2. B.Turndown ratio
3. C.HART protocol
4. D.Orifice plate flow measurement

Answer + AI explanation with Pro

1. A.Turndown ratio — ratio of maximum to minimum flow a meter reads within stated accuracy, about 4:1 for orifice plates against 20:1 or more for Coriolis
2. B.Turndown ratio — digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring
3. C.Turndown ratio — standard analogue transmitter output where 4 mA is zero of range; the live zero lets a broken wire (0 mA) be distinguished from a true zero
4. D.Turndown ratio — vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run

Answer + AI explanation with Pro

1. A.bluff body sheds vortices at a frequency proportional to velocity, well suited to steam and gas, but reads zero below a minimum Reynolds number
2. B.platinum resistance element reading 100 Ω at 0 °C and about 0.385 Ω per °C, more accurate and linear than a thermocouple but limited to about 600 °C
3. C.vibrating tube whose phase shift between inlet and outlet sensors is proportional to mass flow, also giving density and needing no straight run
4. D.differential pressure across a sharp-edged restriction where flow is proportional to the square root of DP, so the transmitter needs square-root extraction

Answer + AI explanation with Pro

1. A.4–20 mA signal
2. B.DP level measurement
3. C.HART protocol
4. D.Vortex flow meter

Answer + AI explanation with Pro

1. A.Vortex flow meter — hydrostatic head between bottom and top taps gives liquid level; a wet leg on the low side requires zero elevation or suppression
2. B.Vortex flow meter — bluff body sheds vortices at a frequency proportional to velocity, well suited to steam and gas, but reads zero below a minimum Reynolds number
3. C.Vortex flow meter — digital signal superimposed on the 4–20 mA loop so a handheld or DCS can read diagnostics and re-range the transmitter without rewiring
4. D.Vortex flow meter — two dissimilar-metal junctions generating a Seebeck voltage proportional to temperature difference; K type (chromel-alumel) covers up to about 1200 °C

Answer + AI explanation with Pro