81
Scope Multimeter
General Reference
Horizontal Scale
See Sweep Scale
Invert
Function used to switch signal polarity,
Lambda (l)
Used to represent a numerical value denoting the actual
measured air/fuel ratio with respect to the ideal air/fuel ratio at
stoichiometry. Lambda equals one (1) when the actual air/fuel
ratio is equal to the theoretical (stoichiometric) air/fuel ratio of
14.7 (14.66) to 1. Lambda less than 1 means excess fuel;
greater than 1 means excess air.
Megasamples per second (MS/s)
Sample rate unit equal to one million samples per second
Noise or Hash
Unwanted voltage, current or signal interference that is
imposed on a signal.
Parasitic Voltage
Trace voltage in a circuit after the main power source is
disconnected.
Peak
The maximum amplitude value present in a varying or
alternating voltage. This value may be either positive or
negative.
Peak Detect
Peak detect captures and evaluates all signal sample points,
in order to display fast occurring events or glitches.
Pressure Transducer
Electronic device that converts pressures (negative/positive) to
electrical signals.
Pulse
A signal with abrupt (fast) signal direction changes in a positive
or negative direction, with consistent level and duration.
Pulse Period
One complete on and off cycle or time period.
Pulse Train
Collection of signal pulses traveling together.
Pulse Width (duration)
Measurement of a signals on time in a circuit that pulses on
and off. Specified in units of time.
Pulse Width Modulation (PWM)
A signal that continuously cycles on and off while the on-time
varies within each cycle.
RMS
The RMS (root mean square) value of alternating currents and
voltages is the effective current or voltage applied, rather than
the peak current or voltage measurable. The AC RMS voltage
value can be defined as the equivalent DC voltage of the AC
voltage measured. RMS values are commonly used in AC
electrical measurement, as they are more representative of
DC measurements.
Sample Rate
Number of times (frequency) the scope/meter takes a sample
of the signal. Specified in mega samples per second (MS/s).
Sampling
Process of obtaining a sequence of instantaneous values for a
signal at regular or intermittent intervals. When a quantity of
samples are collected the operational status of the device is
determined.
Screen Update Rate
How often the captured data is (updated) displayed on the
screen.
Signal
Detectable voltage, current, or magnetic field, by which
specific information is transmitted in an electronic circuit or
system.
Square Wave
A square or rectangular waveform (digital) which alternately
switches high to low (on/off) for specific lengths of time, that
has very fast rise and fall times.
Sweep Scale
The horizontal scale on the grid. Also referred to as time scale
or x axis.
Term / Abbreviation
Description
