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Keysight 53210A/53220A/53230A Assembly Level Service Guide
Protection limits
The Keysight 53210A/53220A/53230A 350 MHz Universal Frequency Counter/
Timer provides protection circuitry to prevent damage to the instrument and to
protect against the danger of electric shock, provided the Protection Limits are
not exceeded and the instrument is properly grounded. To ensure safe operation
of the instrument, do not exceed the Protection Limits defined on the front panel:
WARNING
Do not connect the input channels of the 53210A/53220A/53230A to AC
line-voltage mains or to circuits derived from AC mains. The instrument
must be used in CAT I (isolated from mains) applications only. Do not use in
other IEC Measurement Category (CAT II, CAT III, or CAT IV) applications.
Failure to observe these precautions may result in electric shock and serious
personal injury.
WARNING
The BNC shells of the input terminals are connected to the instrument
chassis. Verify signal polarity before making any connections to the input
terminals.
1 Watt Max into 50W
!
Channel / Setup
WARNING
During battery operation, the maximum measured signal supplied by the
user is +42 V.
WARNING
Product Options 201/202 add parallel Channel 1 and Channel 2 inputs to the
rear panel of the instrument. Signals on the center conductor of either
panel’s channel BNCs are also present on the corresponding center
conductor of the BNC on the opposite panel.