iET PRS-330 series, Operation Manual, Page: 58 / 67

PRS-330 Series
PRS-DMM SOFTWARE 46
9.3.4 Adjust PRS
Clicking on the Adjust PRS key will step the
operator through the PRS-330 adjustment
procedure. The procedure consists of measuring
all 43 internal resistors using the DMM and
storing the actual resistance values into a table.
These resistance values are used in the algorithm
to create the programmed resistance value. See
section 8.1.4 for more information.
9.3.5 PRS-DMM Speed
There are three selections for PRS-DMM Speed.
These selection affect the accuracy from the
target value and time to make the measurements.
Slow measurements are made with 7 ½ digits of
resolution, and measurements and adjustments
are made until the accuracy is better than ±20
ppm.
Medium measurements are made with 6 ½ digits
of resolution and measurements and adjustments
are made until the accuracy is better than 40 ppm.
Fast measurements are made with 6 ½ digits
of resolution. There are no adjustments made
in fast mode. The value from the DMM is just
displayed.
The uncertainty of the measurement is also
displayed. The uncertainty is based upon the
speci
fi cations given in the manual for the Fluke
8508A or Agilent 3458A. The uncertainty is
based upon either 6 ½ or 7 ½ digits of resolution,
absolute uncertainty for 365 days and a 95%
con
fi dence level.