cwea Grade 4 Test Part 2
Acid: - Correct Answer A substance which releases hydrogen ions
when dissolved in water. Most acids will dissolve the common metals and will react with a base to form a neutral salt and water. An acid is the opposite of an alkali, has a pH rating lower than 7.0, will turn litmus paper red, and has a sour taste.
Acidity: - Correct Answer The quantitative capacity of water or a
water solution to neutralize an alkali or base. It is usually measured by titration with a standard solution of sodium hydroxide, and is expressed in ppm or mg/L of its calcium carbonate equivalent.
Accuracy: - Correct Answer The difference between the readings
of an instrument and true value of what is being measured, expressed as a percent of full instrument scale.
Air Gap: - Correct Answer A clear vertical space through the free
atmosphere, between the lowest opening of any pipe or faucet conveying water or waste to a tank plumbing fixture receptor or other device, and the flood level rim of the receptacle. An air gap is used to prevent cross connection between a water treatment device and a possible source of wastewater, thereby preventing a reverse flow of water from the sewer into the water supply system. Without an air gap, such reverse flow could occur due to an increase in the pressure in the sewer system or the creation of a negative pressure in the water supply line. Local plumbing codes usually require the air gap to be twice the diameter of the inlet, with a minimum width of 1.5 inches.
Alternating current (AC Power): - Correct Answer Electrical current
that alternates direction in cycles called hertz.
American Wire Gage (AWG): The U.S. standard
for wire size.
Alkalinity: - Correct Answer The quantitative capacity of water to
neutralize an acid; that is, the measure of how much acid can be added to a liquid without causing a significant change in pH. Alkalinity is not the same as pH because water does not have to 1 / 4
be strongly basic (high pH) to have a high alkalinity.In the water industry, alkalinity is expressed in mg/L of equivalent calcium carbonate. There are
three kinds of alkalinity: carbonate, bicarbonate,
and hydroxide alkalinity. Total alkalinity is the sum of all three kinds of alkalinity. Different tests are used to determine the quantity of the different kinds of alkalinities present in water.
Automatic Controller: - Correct Answer A device that measures the
value of a variable and operates to correct or limit deviation from a selected reference. It includes means for both measurement and control.
Automatic Control System: - Correct Answer Any combination of
automatic controllers connected in closed loops with one or more processes.
Automation: - Correct Answer The employment of devices, which
automatically control one or more functions in an industrial process.
Autotransformer: - Correct Answer A transformer used to step
voltage up or down. The primary and secondary windings share common turns, and it provides no isolation.
Auxiliary Source: - Correct Answer A power source dedicated to providing
emergency power to a critical load when commercial power is interrupted.
BTU: - Correct Answer British Thermal Unit. The energy required to
raise one pound of water one degree Fahrenheit.One pound of water at 32°F requires the transfer of 144 BTUs change from liquid into solid ice.
Balanced Load: - Correct Answer An alternating current power system
consisting of more than two current-carrying conductors, in which these conductors all carry the same current.
Backbone: - Correct Answer The major multi-channel link in a network,
from which smaller links branch.Battery - Correct Answer A collection of cells, grouped together to provide higher voltage and /or higher current than 2 / 4
a single cell.
Blackout: - Correct Answer A total loss of commercial power.
Bonding: - Correct Answer Deliberate connection of two or more
points to reduce any difference of potential (voltage).
Branch Circuit: - Correct Answer A division of a load circuit, with
current limited by a fuse or circuit breaker.
Break-Before-Make: - Correct Answer Operational sequence of a
switch or relay where the existing connection is opened prior to making the new connection.
Brownout: - Correct Answer A low-voltage condition lasting longer
than a few cycles. Brownouts differ from outages only in duration.
Buck-Boost Transformer: - Correct Answer A small, low-voltage
transformer placed in series with the power line to increase or reduce steady-state voltage.
Busbar: - Correct Answer A heavy, rigid conductor used for high
voltage feeders.CM: Common Mode. - Correct Answer The term refers to electrical interference which is measurable as a ground-referenced signal. In true common mode, a signal is common to both the current-carrying conductors.
CPU: - Correct Answer Abbreviation for Central Processing Unit,
which is pronounced as separate letters. The CPU is the brain of the computer. Sometimes referred to simply as the processor or central processor, the CPU is the most important element of the computer system.
Calibration: - Correct Answer The procedure laid down for determining,
correcting, or checking the absolute values corresponding to the graduations on a measuring instrument.
Capacitance: - Correct Answer A measure in units of quantity that
is determined by the type of quantity contained and the type of reference variable.Capacitor: - Correct Answer Two plates or conductors separated by 3 / 4
an insulator. Applying a voltage across the plates causes current to flow and stores a charge.Capacitors resist changes in voltage.
Chemical Oxygen Demand (COD): - Correct Answer A measure of the oxygen-
consuming capacity of organic matter present in water or wastewater. COD is expressed as the amount of oxygen consumed from a chemical oxidant in milligrams per liter during a specific test.Chlorinator: - Correct Answer Chlorinator: A mechanical device specifically designed to feed chlorine gas or pellets, or a solution such as hypochlorides, into a water supply in proportion to the flow of water.
Chlorine: - Correct Answer A chemical widely used in the disinfection
of water and as an oxidizing agent for organic matter, iron, hydrogen sulfide, etc. It is available as a gas, as a liquid in sodium hypochlorite, or as a solid in calcium hypochlorite. In water, chlorine reacts with organics to form trihalomethanes (THM) which can cause cancer Chlorine Demand: - Correct Answer A measure of the amount of chlorine which will be consumed by organic matter in water before chlorine residual will be found.
Circuit: - Correct Answer The complete path of an electric current,
including the source of the current.
Clamp-on CT: - Correct Answer A current transformer which
clamps around a current-carrying conductor so the conductor does not have to be opened for insertion of the transformer primary. It is particularly suited for monitoring in situations where current must be sensed at many points for relatively short periods.
Closed Loop: - Correct Answer A combination of control units in
which the process variable is measured and compared with the desired value (or set point).If the measured value differs from the desired value, a corrective signal is sent to the final control element to bring the controlled variable to the proper value.
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