User Manual

4
Timebase
Measurement Clock: 50MHz.
Internal Reference oscillator: 10MHz TCXO with electronic calibration adjustment.
Oscillator Temperature Stability: Better than ± 1ppm over rated temperature range.
Initial Oscillator Adjustment Error: < ± 0.2ppm at 21ºC.
Oscillator Ageing Rate: < ± 1ppm first year.
Calibration adjustment range: > ± 8ppm.
Measurement Functions
Frequency (Inputs A, B or C)
A Input Frequency Range:
< 0.001Hz (DC coupled) to >125MHz
B input Frequency Range:
80MHz to >3000MHz.
C input Frequency Range:
<2Ghz to >6GHz.
Resolution:
up to 10 digits (see below) or 0.001Hz
Period (Inputs A, B or C)
A Input Period Range:
8ns to 1000s (DC coupled)
B input Period Range:
0.333ns to 12.5ns
C input Period Range:
0.166ns to 0.5ns
Resolution: up to 10 digits (see below)
Pulse Width Modes (Input A only)
Functions:
Width high or low, ratio H:L (high time to low time) or duty cycle.
Pulse Width Range:
40ns to 1000s
Averaging:
Automatic within measurement time selected, up to 50 pulses.
Resolution: 20ns for one pulse; up to 1ns or 10 digits with multiple pulse
averaging. 0.01% for Ratio H:L and Duty Cycle.
Total Count (Input A only)
Count range:
1 to 9 999 999 999
Minimum pulse width:
8ns
Frequency Ratio B:A
Resolution: Equal to the resolution of the two frequency measurements.
If the ratio exceeds ten digits, displays six digits plus exponent.
Measurement Time
Selectable as 100s, 10s, 1s or 0.3s. The instrument displays the average value of the input
signal over the measurement time selected, updated every 2s, 1s, 0.5s or 0.3s respectively. The
hardware captures the count values and continues measuring without any dead time.
Resolution
The displayed resolution depends upon measurement time and input frequency. The basic
resolution of period is 8 digits for every 2 seconds of measurement time. Frequency resolution is
the reciprocal of period resolution. Usable resolution can be reduced by noise at low frequencies.
Accuracy
Measurement accuracy is timebase accuracy + measurement resolution + 2 counts.