Contrast The level difference between light and dark.
Continuity Beeper Audible tone emitted from a meter when the resistance falls below
a preset threshold value (typically 100 Ohms).
Cosine F Voltage and Current do not always happen together, often there is a
difference. The difference is an angle between 0 and 90, termed F.
The greater e angle, the bigger the difference between True and
Apparent Power and the smaller the Power Factor. If Voltage and
Current happen at about he same time, F is small, the values of
True and Apparent Power are close, Power Factor approaches 1.
Criterion Sound Level The eight hour average weighted sound level, expressed in dB, that
Level corresponds to the maximum permitted daily exposure to noise
as prescribed in national and state regulations.
Data Acquisition The ability of an instrument to acquire measurement information
as it occurs, and to be able to store it, for future retrieval or
transmission.
Data Logging Typically, the ability of an instrument to store information in non
volatile memory for use later (on demand) for analysis and report
generation.
Data Hold The temporary storage function of a measuring device which holds
a displayed value when a user presses a key or button.
Decibels The unit of measure expressed as dB’s, used when measuring the
level of sound. Every 3dB represents approximately double the
power or sound level, hence 53dB is twice as loud as 50dB. dBm
refers to decibels above one milliwatt.
Differential In dual input measuring devices, differential is the displayed
difference between the two inputs (Input A - Input B = Differential).
Diode Check A function of a measuring device in analyzing the operation of a
diode. The probe leads are attached to either side of the diode and
the user is alerted visually and/or audibly as to the diode’s integrity.
Display Counts The number of display units a meter or other device can indicate.
For example, a 3-1/2 digit display can indicate from 0 - 1,999 and
a 4-1/2 digit display can indicate from 0 - 19,999. If a meter is
bi-polar it can indicate positive and negative depending on the
460 User’s Guide Glossary
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