IET Labs PRS-370 SERIES, Руководство по эксплуатации, Страница: 27 / 54

OPERATION
PRS-370 Series
16
370 pressing the INC and DEC softkeys will
increment the resistance value to the next
resistance value plus or minus the
Set Value .
3.4.5.2 Standard Value
The Standard Value: allows the PRS-370 to be
used as an automated resistance carousel with
built-in EIA “preferred value” resistance tables
of 1% (E96), 5% (E24), 10% (E12) increments
or RATIOMETRIC user speci
fi ed increment.
Figure 3-4 Standard Values Menu
Resistors are available in a number of standard
ranges, often called ‘preferred values’ These
ranges, or series, are set out by the Electronic
Industries Association (EIA), and common
values are E12, E24, E48, and E96. The number
after the ‘E’ denotes the number of resistance
values the series contains per decade.
The series are logarithmic and are derived from
the resistor tolerance; resistors with a tighter
tolerance can have more values in the series
that won’t overlap one another. The series are
sometimes referred to by the tolerance, the two
being related as follows:
E12: 10% tolerance
E24: 5% tolerance
E48: 2% tolerance
E96: 1% tolerance
When a Standard Value: is selected on the
PRS-370 pressing the INC and DEC softkeys
will increment the resistance value to the next
“preferred” resistance value.
RATIOMETRIC allows a custom tolerance value
to be entered by the user. The default value is
0.8% but can be set to the required value in %.