Input Terminal Measurement Limits; Sense Terminal Measurement Limits - Keysight Truevolt Series Operating And Service Manual

Safety and Regulatory Information
For the 34461A, 34465A, and 34470A, the Front/Rear switch selects the terminal set to be
used. DO NOT operate this switch while signals are present on the front or rear terminals.
The user-replaceable 3 A current-protection fuse is on the rear panel. There are 3 A and 10 A
(34461A, 34465A and 34470A) current-protection fuses located inside the unit. Contact your
Keysight Sales and Service Center or refer to product service documentation for replacement
instructions.
To maintain protection, replace fuses only with

Input Terminal Measurement Limits

Measurement Limits are defined for the input terminals:
Main Input (HI and LO) Terminals. The HI and LO input terminals are used for voltage, resistance, fre-
quency (period), capacitance, and diode test measurements. Two Measurement Limits are defined for
these terminals:
HI to LO Measurement Limit. The Measurement Limit from HI to LO (Input terminals) is 1000 VDC or
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750 VAC, which is also the maximum voltage measurement. This limit can also be expressed as 1000
Vpk maximum.
LO to Ground Measurement Limit. The LO input terminal can safely "float" a maximum of 500 Vpk
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relative to ground, where ground is defined as the Protective Earth Conductor in the AC mains power
cord connected to the instrument.
As implied by the above limits, the Measurement Limit for the HI input terminal is a maximum of 1500 Vpk
relative to ground when LO is at its maximum of 500 Vpk relative to ground.
Current Input Terminal. The current input ("I") terminal has a Measurement Limit of 3 A or 10 A (DC or
AC) between the "I" terminal (3 A or 10 A) and the LO input terminal. Note that the current input terminals
will always be at approximately the same voltage as the LO terminal, unless a current protection fuse is
open. The 10 A terminal is not available on the 34460A.

Sense Terminal Measurement Limits

The HI and LO sense terminals are used for DCV ratio measurements and four-wire resistance and tem-
perature measurements. The Measurement Limit is 200 Vpk for all of the terminal pairings: LO sense to LO
input, HI sense to LO input, and HI sense to LO sense.
The 200 Vpk limit on the sense terminals is the Measurement Limit. Operational voltages in resistance meas-
urements are much lower – up to ± 12 V in normal operation.
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fuses of the specified type and
Keysight True volt Series Operating and Service Guide
rating.