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61 Cards in this Set
- Front
- Back
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Bimetallic thermometer |
- A thermometer that uses a strip of two metal alloys with different coefficients of thermal expansion that are fused together at the ends. - used to measure thermometers from 300 degrees Fahrenheit to 800 degrees Fahrenheit. |
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Magnetostrictive Sensor |
Part of a level-measuring system for boiler water consisting of an electronics module, a waveguide, and a float containing a magnet that is free to move up and down a brass rod pipe inserted into a vessel from the top |
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Venturi Tube |
A flow restriction device consisting of a fabricated pipe section with a converging inlet section, a straight throat, and a diverging outlet section |
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Digital Control System |
An integrated system of control loops that use digital control signals to control a process |
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Control valve |
A final element that is used to modulate fluid flow in response to signals from a control element |
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* Opacity Analyzer |
- A stack analyzer consisting of a focused light source and an analyzer that measures the received light intensity. - stack gas opacity is measured to determine the amount of particulate matter in the gases of combustion. - an opacity smoke indicator alarm can be used to indicate an unexpected amount of particulate matter in the gases of combustion. |
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Thermocouple |
- A thermometer consisting of two dissimilar metals that are joined together to form a circuit that generates a voltage proportional to the difference in temperature between the hot and cold ends of the wires. - the hot end of wires are exposed to the area needing temperature measurement and the cold end of the wires are exposed to ambient temperature. - permit rapid, accurate temperature readings over a wide range. - usually connected to a transmitter. - commonly used to measure the furnace temperature or the temperature of the gases of combustion, but it’s not limited to measuring those only. |
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Manometer |
- A draft gauge that measures pressure with a liquid-filled tube. - typically one side is open to the atmosphere. - can be a U-tube or inclined-tube gauge. |
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Pneumatic Level Control and/or Displacer |
A level-measuring instrument consisting of a cylinder, heavier than the liquid in which it is immersed, connected to a spring or torsion device that measures its weight |
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Regulator |
A self-operating control valve used for pressure and temperature control |
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* Resistance Temperature Detector (RTD) |
- An electronic thermometer consisting of a high-precision resistor with resistance that varies with temperature. - accurate and reliable temperature sensors, especially for low temperatures and small ranges. - typical applications include: monitoring bearing temperatures, monitoring fan motors for overheating, and as a substitute for thermocouples where precise and stable temperature measurements are required. |
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Control Element and/or Controller |
A device that takes an input signal, compares the signal to a setpoint, performs a computation, and sends an output signal to a final element |
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Pneumercator and/or Bubbler |
A level-measuring instrument consisting of an air tube extending to the bottom of a tank, a pressure gauge and transmitter, a flow-control meter, and a pressure regulator |
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Control Device and/or Final Element |
A device that controls the flow of liquid, gas or air, or electrical current |
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Coriolis Flow Meter |
A meter that measures the mass flow rate of a fluid |
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Orifice Plate |
A flow restriction device consisting of a thin circular metal plate with a sharp-edged hole in it and a tab that protrudes from a flange |
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Analyzer Sampling System |
A system of piping, valves, and other equipment used to extract a sample from a process, condition it if necessary, and convey it to an analyzer |
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Positive-Displacement Flow Meter |
A flow meter that admits fluid into a chamber of known volume and then discharges it |
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Actuator |
A device that provides the power and motion needed to manipulate the moving parts of a valve or damper used to control fluid flow through a final element |
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Transducer |
A device that receives a signal representing a variable, such as temperature, pressure, or flow, and converts that signal into an electrical or digital signal that is compatible with a digital control system |
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Programming Device |
A device used to control the actions of a PLC, DDC system, or computer |
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* Damper |
An adjustable blade or set of blades used to control the flow of air |
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Transmitter |
A device that conditions a low-energy signal from a sensor and produces a suitable signal for transmission to other components or devices |
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pH meter |
- A water analyzer used to monitor the acidity or alkalinity of the boiler water. |
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Control Loop |
A system that consists of a primary element and transmitter, a control element, and a final element |
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Variable-Area Flow Meter |
A meter that maintains a constant differential pressure and allows the flow area to change with the flow rate |
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Primary Element and/or Sensor |
A device that measures a process variable and produces a usable output in the form of mechanical movement, electrical output, or instrument air-pressure output |
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Thermometer |
The general term for an instrument used to measure temperature |
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Diaphragm Draft Gauge |
A draft gauge that measures draft using a flexible diaphragm connected with linkage to a pointer on a scale that is calibrated in inches or fractions of an inch of water column |
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Vacuum Gauge |
- A pressure gauge used to measure pressure less than atmospheric pressure. - typically calibrated to read inches of Mercury from 0” Hg to 30” Hg. - Bourdon tubes are common on these gauges. |
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Float |
A level-measuring instrument with a hollow ball attached to it that floats on top of a liquid in a tank |
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Ultrasonic Sensor |
A level-measuring instrument that uses an ultrasonic signal to measure level |
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Rotameter |
A variable-area flow meter consisting of a tapered tube and a float with a fixed diameter |
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Draft gauge |
- A pressure gauge used to measure the difference in draft pressure between the atmosphere and a furnace, breeching, or stack. - two types are: monometers and diaphragm draft gauges. - improper pressure can result in gas leaks in the boiler room and unneeded air leakage into the boiler. |
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* Conductivity probe |
-A water level indicator that senses the boiler water level by detecting a change in current flow as water covers or uncovers the end of the probe. - it can be used as a level indicator, a high water or low water alarm switch, or a feedwater pump ON or OFF switch. |
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Solenoid Valve |
An electrically operated control valve that quickly adjusts a valve to an open or closed position. |
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Pressure Regulator |
An adjustable valve that is designed to automatically control the pressure downstream. |
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Pilot-operated pressure regulator |
A regulator that uses upstream fluid as a pressure source to power the diaphragm of a larger valve. |
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Guided-wave radar |
A water level indicator that uses a radar pulse that is sent down a waveguide that extends into the water to calculate the level based on the radar transit time. |
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Magnetic Float Indicator |
A water level indicator that consists of a tube chamber and an internal float. |
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Instrumentation |
- A group of measuring instruments and related devices that are part of a monitoring and control system. - used to measure the operating conditions of a boiler. |
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Pressure Gauges |
- used to measure pressure at various points within a boiler system. - they can measure air pressure, gas pressure, steam pressure, vacuum pressure, and discharge pressures on fuel and water lines. |
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Vacuum and Compound Gauges Picture |
Back (Definition) |
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Draft Gauges Picture |
Back (Definition) |
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Pressure Gauges Picture |
Back (Definition) |
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Steam Siphons Picture |
Back (Definition) |
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Gauge Glass |
- A water level indicator that consists of glass that allows a direct view of the water level. - ASME code requires that high pressure steam boilers be equipped with at least one. - steam boilers operating at 400 psi and up have either two of these or one and an electrical level indicator. - the common types are tubular, flat glass, reflex, and ported. |
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Thermocouples Picture |
Back (Definition) |
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Resistance Temperature Detectors (RTDs) |
Back (Definition) |
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Resistance Temperature Detectors (RTDs) Picture |
Back (Definition) |
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Bimetallic Thermometers Picture |
Back (Definition) |
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Gauge Glasses Picture |
Back (Definition) |
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Conductivity Probes Picture |
Back (Definition) |
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Flow Meters |
- used to measure the flow rate of liquid, gas, or steam in a pipe or duct. - used for air, water, steam, fuel oil, and gases. |
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Differential-Pressure Flow Meters |
- can be used to measure the flow of air, steam, or other gases. - easy to use and very reliable. - a pipeline flow restriction is used to cause a pressure drop as fluid flows through the restriction. - most common restriction devices are an orifice plate and a Venturi tube. |
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Lock out tag out (LOTO) |
The use of locks, chains, or other physical restraints to positively prevent the operation of specific equipment. After locking, a process of attaching a danger tag to the source of power to indicate that the equipment may not be operated until the tag is removed is performed. |
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Conductivity Meters |
- consists of two electrodes immersed in a solution that measure the conductivity of the solution. - used to measure the total dissolved solids in the water. |
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Differential-Pressure Flow Meters Picture |
Back (Definition) |
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Conductivity Meters Picture |
Back (Definition) |
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Boiler Water pH Measurement Picture |
Back (Definition) |
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Annunciator |
- an audible alarm that is created electrically or electronically. - common alarms indicate general plant conditions that need operator attention. - dedicated alarms provide indications as to the cause of a problem. |
