60 Questions
Which type of RTD is used when very high accuracy is needed?
4-wire configuration
What is the advantage of using a 3-wire RTD over a 2-wire RTD?
Higher accuracy
What type of temperature device exhibits a positive change in resistance for a positive change in temperature?
RTD
Which standard instrumentation signal is most commonly used for temperature measurement?
Current - 4 to 20mA
Which type of process measurement detects the process variable within a range of all possible values at all times?
Continuous Measurement
Which type of measurement device is in direct contact with the process and may change the process or be a source of contamination?
Direct or Invasive Measurement
Which term refers to the difference between the desired setting of the process variable and the current measured condition of the process?
Error
What is the lowest value that corresponds to the bottom or lowest limit of the process called?
Zero
Which two colors are used to identify the 'J' type thermocouple?
White and red
What is the purpose of the HART protocol?
To enable bidirectional communication between smart devices and control/monitoring devices
What is the process variable represented by 'URV' in the HART protocol?
Upper Range Value
Why does HART communication require a minimum loop resistance?
To enable FSK HART signal detection
According to the text, what is the formula to convert the nonstandard signal input (°C) into a percent?
$% = PV - LRV \times 100$
According to the text, what is the formula to calculate the output into the standard signal (mA)?
$Output = (Input - LRV) \times Span + LRV$
Based on the given information, what should the psi output signal be if the input range is 4-20mA and the PV is 13.6 mA?
10.2 psi
According to the text, what is the simplified formula for cold junction compensation?
$V_{true} = V_{meas} + V_{ref}$
Which organization is responsible for standardizing P&ID symbols?
ISA
What is the span of a thermometer with a scale from -40°C to 100°C?
140°C
What is the purpose of a transmitter in process control?
To convert non-standard signals to standard instrumentation signals
What is the most common material used for resistive temperature detectors (RTDs) in industry?
Platinum
Which type of level measurement involves detecting the level of solids as well as liquids?
Solid level measurement
Why are regular performance verifications necessary for process instrumentation?
All of the above
Which quality program dictates periodic calibration to recognized standards for all instruments that impact product quality?
ISO 9000
What are some factors that can cause the performance of instruments to change over time?
All of the above
What are some problems that regular performance checks can uncover?
All of the above
What is level measurement?
The act of detecting the interface or boundary between materials
According to the text, what are the basic electrical equations used in instrumentation?
$E=I \times R$ and $P=E \times I$
What is the order of operations for solving equations?
Solve brackets first, then solve exponents, perform multiplication and division from left to right, perform addition and subtraction from left to right
What is the formula to calculate the percentage of a process variable?
$% = \frac{PV - LRV}{Pspan} \times 100$
What is the formula to convert a percentage to a standard signal?
$mA = \frac{%}{100} \times Pspan + LRV$
Point Measurement detects the process variable at a predetermined ______ or value
point
Continuous Measurement detects the process variable within a ______ of all possible values at all times
range
Direct or Invasive Measurement: The measurement device will be in direct ______ with the process
contact
Indirect or Non-Invasive Measurement: No ______, good for extreme processes
contact
_______ are parts of the process control that perform the function of measuring and changing the process.
Devices
Devices that measure the process are called _______.
sensors or elements
Instrumentation devices that convert non-standard signals to standard instrumentation signals are called _______.
transmitters
According to the text, what is the formula to convert the nonstandard signal input (°C) into a percent?
$% = \dfrac{PV - LRV},{Ps_{pan}} \times 100$
Devices that create changes in a process are called _______.
actuators
What is the lowest value that corresponds to the bottom or lowest limit of the process called?
LRV
What is level measurement?
The process of determining the height of a substance in a container or vessel
Why are regular performance verifications necessary for process instrumentation?
To ensure accuracy and reliability of measurements over time
An RTD is a temperature device/sensor that will exhibit a positive change in ______ for a positive change in temperature.
resistance
The 2-wire RTD is only used for short distances and where high accuracy isn’t necessary because you are adding the resistance in the leads to the resistance of the ______.
sensor
The 3-wire RTD is the most common because you can subtract the ______.
lead resistance
The 4-wire RTD is used when very high accuracy is needed. With the 4-wire configuration, the instrument will pass a constant current (I) through the outer leads. The addition of the two additional leads makes it possible to eliminate errors due to change in ______ resistance.
lead wire
According to the text, the HART protocol provides data between intelligent field instruments and DCS/PLC or handheld communicators through ________ communication.
bidirectional
The HART protocol makes use of Bells 202 Frequency Shift Keying (FSK) standard to superimpose digital information on the conventional 4-20 mA ________.
analog signal
The microprocessor-based field devices that offer better accuracy, long-term stability, and reliability than conventional analog instruments are known as ________ instruments.
smart
The HART protocol uses analog and digital ________ simultaneously for communication.
communication
According to the text, what is the formula to convert the nonstandard signal input (°C) into a percent?
$%=\dfrac{PV - LRV},{Span} \times 100$
Based on the given information, what should the psi output signal be if the input range is 4-20mA and the PV is 13.6 mA?
$\text{Output} = \left(\dfrac{Input - LRV_{\text{input}}},{Span_{\text{input}}} \right) \times Span_{\text{output}} + LRV_{\text{output}}$
According to the text, what is the simplified formula for cold junction compensation?
$V_{\text{true}} = V_{\text{meas}} + V_{\text{ref}}$
What is the purpose of the HART protocol?
to enable communication between smart field devices and control systems
Regular performance verifications with a suitable reference standard, are necessary because regulations governing occupational safety, environmental protection, and consumer safety often require evidence of traceable calibration for process instrumentation. Quality programs, such as ISO 9000, dictate periodic calibration to recognized standards for all instruments that impact product quality. Calibration is still required The performance of instruments will changeover time with exposure of the transmitter and the primary sensing element to temperature, humidity, environmental pollutants and vibration. Regular performance checks can uncover problems not directly caused by the equipment such as plugged impulse lines, or pressure lines that have become filled with condensate. Or the wrong ______ type installed.
thermocouple
Level detection of solids can be more difficult than with liquids because solids will not take the shape of the vessel and can bridge the detection points (Primary Elements). In defining level measurement, we can say that : Level measurement is the act of detecting the interface or ______ between.
boundary
Level measurement is divided into two familiar types of detections. ______ and Continuous level measurement.
Point
Regular performance verifications with a suitable reference standard, are necessary because regulations governing occupational safety, environmental protection, and consumer safety often require evidence of traceable calibration for process instrumentation. Quality programs, such as ISO 9000, dictate periodic calibration to recognized standards for all instruments that impact product quality. Calibration is still required The performance of instruments will changeover time with exposure of the transmitter and the primary sensing element to temperature, humidity, environmental pollutants and vibration. ______ performance checks can uncover problems not directly caused by the equipment such as plugged impulse lines, or pressure lines that have become filled with condensate. Or the wrong thermocouple type installed.
Regular
Level measurement can involve detecting the level of solids as well as ______‘s.
liquid
Introduction to Level Measurement Level is simply the height that some material fills a container. Level measurement is an integral part of process control systems for inventory control, quality and safety. Level measurement is divided into two familiar types of detections. Point and Continuous level measurement. Level measurement can involve detecting the level of solids as well as ______‘s. Level detection of solids can be more difficult than with liquids because solids will not take the shape of the vessel and can bridge the detection points (Primary Elements). In defining level measurement, we can say that : Level measurement is the act of detecting the interface or boundary ______.
liquid
Test your knowledge on different types of thermocouples and their designations by taking this quiz. Learn about the colours associated with different thermocouple types and their polarity. Explore the various combinations of alloys and metals used in thermocouples.
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