18WuD2x

zero potential • zero-zero 769
zero potential 1. Complete absence of voltage.
2. In some circuits, the lowest voltage, to which
all other voltages are referred. 3. The potential of
the earth as a reference point.
zero power 1. Complete absence of dissipated
power. 2. In some circuits and systems, the lowest
power level, to which all other power values
are referred.
zero-power resistance In a thermistor, the resistance
at which power dissipation is zero.
zero-power resistance-temperature characteristic
For a thermistor, a figure that reveals the extent
to which zero-power resistance varies with
the temperature of the thermistor body.
zero-power temperature coefficient of resistance
A temperature coefficient that reveals
the extent to which the temperature of the thermistor
body causes the zero-power resistance to
change (expressed in ohms per ohm per degree
Celsius).
zero reactance 1. Absence of reactance (a theoretically
ideal condition in alternating-current circuits).
2. In some circuits, the lowest reactance,
to which all other reactances are referred.
zero resistance 1. Absence of resistance (a theoretically
ideal condition). 2. In some circuits, the
lowest resistance, to which all other resistances
are referred.
zero scale current In a digital-to-analog (D/A)
converter, the current into the output when all
logic inputs are low (off) and the output is at a
certain predetermined value, in microamperes or
milliamperes.
zero screw The mechanical zero adjuster of a
meter.
zero set 1. A (usually screwdriver-adjusted) mechanism
for setting the pointer of a meter to zero.
2. An electrical circuit consisting of a resistance
bridge or adjustable bucking voltage for setting a
meter to read zero under specific conditions.
VTVM
circuit
R2
R3
zero set, 2
Meter
(dc µA)
R4
R1
Zero-set
control
B
B
zero shift See ZERO DRIFT.
zero signal 1. The condition of complete absence
of signal. 2. A finite signal level used as a reference
point against which all other signal levels
are measured.
zeros of impedance For an alternating-current
network, the frequencies at which the impedance
is zero. Also called zeros.
zeros of network function The real or complex
values at which the network function is zero.
Compare POLES OF NETWORK FUNCTION.
zeros of transfer function The frequencies at
which a transfer function becomes zero. Compare
POLES OF TRANSFER FUNCTION.
zero stability Constancy of the zero condition in an
instrument or system (i.e., absence of zero drift).
zero state The low, zero, off, or false logic state of a
bistable device, such as a flip-flop or magnetic
cell. It might be actual zero output or a low-voltage
output. Compare ONE STATE. In binary
notation and calculation, the zero state is
represented by a cipher.
zero suppression 1. In computer operation, automatic
nonsignificant leading-zero cancellation.
2. Absence or removal of a restraining medium,
such as a noise-suppression voltage. 3. In an audio
recording system, the introduction of a voltage
to cancel the steady-state component of the
input signal.
zero temperature 1. The point from which temperatures
are reckoned on a thermometer scale.
On the Celsius (centigrade) scale, zero degrees
corresponds to the freezing point of pure water at
standard atmospheric pressure. On the Fahrenheit
scale, zero degrees is 32 degrees colder than
the freezing point of pure water at standard atmospheric
pressure. On the Kelvin or Rankine
scales, zero degrees corresponds to the complete
absence of thermal energy; it is the coldest possible
temperature. 2. A temperature point relative
to which all other temperatures are reckoned.
zero temperature coefficient A temperature coefficient
having the value zero (i.e., one that indicates
there is no temperature-dependent drift of a
given quantity).
zero terminal See ZERO-INPUT TERMINAL and
ZERO-OUTPUT TERMINAL.
zero time 1. In some measurements, the first instant
of time, to which all other instants are referred.
2. See ZERO PHASE.
zero time reference During one cycle of radar operation,
the time reference of the schedule of
events.
zero vector A vector whose magnitude is zero.
zero voltage See ZERO POTENTIAL.
zero voltage coefficient A voltage coefficient having
the value of zero (i.e., one that indicates there
is no voltage-dependent drift of a given quantity).
zero-zero The atmospheric condition in which the
ceiling and visibility both are zero (i.e., extremely
dense fog).