26 Agilent U1251A/U1252A User’s and Service Guide
1 Getting Started Tutorial
Selection of Display by 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 secondary display and
frequency on primary display. Alternatively, pulse width
(ms) or duty cycle (%) can appear on the primary display by
pressing again. This enbles 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.
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 (%)
(AC + DC voltage)
[for U1252A]
Frequency (Hz) AC + DC mV
Pulse width (ms)
Duty cycle (%)