Pendulum CNT-90 Series User Manual

Measuring Functions
Phase
What is Phase?
channel B are enough to calculate the result,
including sign.
Phase is the time difference between two sig-
nals of the same frequency, expressed as an
angle.
Resolution
Fig. 4-19
Phase delay.
The traditional method to measure phase de-
lay with a timer/counter is a two-step process
consisting of two consecutive measurements,
first a period measurement and immediately
after that a time interval measurement. The
phase delay is then mathematically calculated
as:
360°x (Time Interval A- B )
Period
or in other words:
Phase A -B = 360°x Time Delay x FREQ
A somewhat more elaborate method is used in
these counters. It allows the necessary mea-
s
urements to be performed in one pass by us-
ing tim
e-stamping. Two consecutive
time-stamps from trigger events on channel A
and two corresponding time-stamps from
Fig. 4-20
Traditional phase definition.
The frequency range for phase is up to 160
MHz and the resolution depends on the
frequency. For frequencies below 100 kHz
the resolution is 0.001° and for frequencies
above 10 MHz it is 1°. It can be further
improved by averaging through the built-in
statistics functions.
Possible Errors
Phase can be measured on input signal fre-
quencies up to 160 MHz. However, at these
very high frequencies the phase resolution is
reduced to:
100ps x 360° x FREQ
4-20
USER MANUAL ● CNT 9x Series ● Rev.22 February 2020

Pendulum CNT-90 Series Specifications

General

Brand	Pendulum
Model	CNT-90 Series
Category	Measuring Instruments
Language	English