I do an evaluation on the 4227. I use picoscop6, 2 Channels, no Trigger,
dc coupling, autorange, samplerate 1.5626Ms/s, 50ms acquisition time,
78130 samples per channel. I save the data in an .txt file, three columns:
time, channel 1, channel 2.
My analog signal is a 1.5Vpp sine, 200Hz from a hp signal Generator. The
signal is applied to two voltage dividers, 100R by 100R. The output signal
of the two voltage dividers is fed into the two channels of the 4227.
I analyze the two signals with a matlab script. I do a fft and calculate
the phase shift between the two signals.
I exspect a constant value, close to zero.
I do get ( 7 measurements ):
-8.6792e-004 rad, -8.2561e-004 rad, -8.8991e-004 rad, -8.9823e-004 rad,
-8.4968e-004 rad, -1.0148e-003 rad, -8.7078e-004 rad
One of the results is more than 10^-4 rad off the mean value, standard
deviation is close to 6e-5 rad.
That is to much for the anticipated use.
Do you see any flaws in the setup?
Faulty software setup?
How do I get a more constant phase delay between the channels?
The 4227 does a multiplexing, using one ADC for two channels?
Are there any other pico products with two ADCs for two channels and
constant phase delay between the channels?
The recorded sample timestamps from the file are not equally spaced,
though the 4227 uses uniform sampling ?! Could this be the problem?
thank you for reading