Snap-On Modis Ultra User Manual page 125

Scope Multimeter
Term / Abbreviation
Horizontal Scale
Invert
Lambda (l)
Megasamples per second (MS/s)
Noise or Hash
Parasitic Voltage
Peak
Peak Detect
Pressure Transducer
Pulse
Pulse Period
Pulse Train
Pulse Width (duration)
Pulse Width Modulation (PWM)
RMS
Sample Rate
Sampling
Screen Update Rate
Signal
Square Wave
Sweep Scale
Description
See Sweep Scale
Function used to switch signal polarity,
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.
Sample rate unit equal to one million samples per second
Unwanted voltage, current or signal interference that is
imposed on a signal.
Trace voltage in a circuit after the main power source is
disconnected.
The maximum amplitude value present in a varying or
alternating voltage. This value may be either positive or
negative.
Peak detect captures and evaluates all signal sample points,
in order to display fast occurring events or glitches.
Electronic device that converts pressures (negative/positive) to
electrical signals.
A signal with abrupt (fast) signal direction changes in a positive
or negative direction, with consistent level and duration.
One complete on and off cycle or time period.
Collection of signal pulses traveling together.
Measurement of a signals on time in a circuit that pulses on
and off. Specified in units of time.
A signal that continuously cycles on and off while the on-time
varies within each cycle.
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.
Number of times (frequency) the scope/meter takes a sample
of the signal. Specified in mega samples per second (MS/s).
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.
How often the captured data is (updated) displayed on the
screen.
Detectable voltage, current, or magnetic field, by which
specific information is transmitted in an electronic circuit or
system.
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.
The horizontal scale on the grid. Also referred to as time scale
or x axis.
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General Reference