HVACR Glossary
Analog
Information communicated by means of a continuously variable signal, using
some property of the medium to convey the signals information. For
example, an aneroid barometer uses angular position as the signal to convey
pressure information. Electrical signals may represent information by
changing their voltage, current, frequency or total charge.
Information is converted from some other physical form (such as sound,
light, temperature, pressure, position) to an electrical signal by a
transducer.
Any change in the analog information is meaningful, and each level of the
signal represents a different level of the event that it represents.
For example, suppose the signal is being used to measure temperature, with
one volt representing one degree Fahrenheit. 10 volts would represent
10 degrees, 10.1 volts would represent 10.1 degrees, etc.
Another example of an Analog control would be a faucet controlling water
from off to full flow, it's variable.
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