User's Manual

16 Agilent U1251A/U1252A User’s and Service Guide
1 Getting Started Tutorial
Selecting display with the Hz button
The frequency measurement feature helps to detect the
presence of harmonic currents in neutral conductors and
determines whether these neutral currents are the result of
unbalanced phases or non- linear loads. Press to access
the frequency measurement mode for current or voltage
measurements — voltage or current on the secondary display
and frequency on the primary display. Alternatively, pulse
width (ms) or duty cycle (%) can appear on the primary
display by pressing again. This enables the
simultaneous monitoring of real- time voltage and current
with frequency, duty cycle, or pulse width. Voltage or
current resumes on primary display after you press and hold
for more than 1 second.
Table 1-7 Selecting display with the Hz button
Rotary switch position (Function) Primary display Secondary display
for U1252A
(AC voltage)
Frequency (Hz) AC V
Pulse width (ms)
Duty cycle (%)
V for U1251A
for U1252A
(DC voltage)
Frequency (Hz) DC V
Pulse width (ms)
Duty cycle (%)
for U1252A
(AC + DC voltage)
Frequency (Hz) AC + DC V
Pulse width (ms)
Duty cycle (%)
(AC voltage)
Frequency (Hz) AC mV
Pulse width (ms)
Duty cycle (%)
(DC voltage)
Frequency (Hz) DC mV
Pulse width (ms)
Duty cycle (%)