Technical data

6 Specifications and Characteristics

94 U3401A User’s and Service Guide

Frequency

• Measurement method

• Reciprocal counting technique. AC coupled input using AC voltage function

• Crest factor

• Maximum 3:0 at full scale

• Signal level

• 10% of range to full scale input on all ranges

• Gate time

• 0.1 s or 1 period of the input signal, whichever is longer.

• Input impedance

• 1 MΩ in parallel with < 100 pF of all ranges

• Maximum input voltage

• 1000 V RMS / 1400 V PEAK

• 2x10

V-Hz product on any range, common mode input

• 1x10

V-Hz product on any range, normal mode input

• Input protection

• 1000 V RMS on all ranges

• Response time

• Approximately 1 second when the displayed reading reaches 99.9% of frequency value.

Measurement Noise Rejection

• Common mode reject ratio (CMRR) for 1 kW unbalanced LO lead

• 50/60 Hz ± 0.1% : DC > 90 dB

• Normal mode rejection ratio (NMRR)

• 50/60 Hz ± 0.1% : > 50 dB

• Response time

• Approximately 1 second when the displayed reading reaches 99.9% of frequenct value.

Table 6 - 9 Measurement specifications (continued)