User Manual    AMETEK Programmable Power 
RS Series    75 
POWER FACTOR  This readout shows the power factor of the load. 
CREST FACTOR  This readout displays the ratio between peak current and rms 
current. 
MEASUREMENT 3 
VOLT THD  This readout displays the total voltage distortion for the selected 
phase. The distortion calculation is based on the H2 through 
H50 with the fundamental voltage (H1) in the denominator. Note 
that other common definitions of THD use the RMS value of the 
voltage as the denominator. This may result in different 
readings between instruments depending on the 
implementation chosen. The mode used by the power source is 
selectable over the bus. 
CURR THD  This readout displays the total current distortion for the selected 
phase. The distortion calculation is based on the H2 through 
H50 with the fundamental current (H1) in the denominator. Note 
that other common definitions of THD use the RMS value of the 
current as the denominator. This may result in different readings 
between instruments depending on the implementation chosen. 
The mode used by the power source is selectable over the bus. 
INST PK CURR  This readout reflects the instantaneous peak current value 
detected at the output. This value is updated continuously and 
does not require a reset operation like the PEAK CURR 
readout. The instantaneous peak current does not use a track 
and hold mechanism like the PEAK CURR measurement in the 
MEASUREMENT 2 screen. Instead, it tracks the peak current 
on a cycle-by-cycle basis. The INST PK CURR typically tracks 
the rms current and the crest factor. 
Update Program Functions from Measurement Screen 
The Shuttle can be used to update program parameters such as voltage, frequency or current 
from the measurement screen.  This can be achieved with the following sequence: 
1.  Select the program 1 screen using the PROG key. 
2.  Use the up and down key to select the desired function to update. (Selects parameter that 
will be changed by the shuttle once in the MEAS1 screen) 
3.  Select the measurement 1 screen by pressing the MEAS key. 
4.  The pointer symbol () points to the programmed parameter (V, F or CL) that will be 
affected by turning the shuttle.