Hi and welcome to scope month! My name is
Daniel Bogdanoff and today we are giving
away eight scopes! It is Friday, March
10th and every Friday I'm giving away two
4000 X-Series scopes on top of the
1000 X-Series scopes that we're giving away each
day in March. We also do a scope tip every
day and since we're giving away 4000s
today, we're going to look at a
scope tip on the 4000 X-Series. So I have
plugged in a 5 volt peak-to-peak sine
wave coming out of my waveform generator,
and normally if you're going to look at
these signals on your device, you're
gonna try and scale your signal and
you're going to get to about there and
see this is too much. I'm losing signal.
And you're going to be happy with scaling
your signal right about there.
As it turns out, the way you scale your
signals actually affects your
measurement integrity. So we're going to
take two sets of measurements- one with
the signal fully scaled on-screen and
one with the signal scaled only a
little bit on the screen. So our first
set of measurements is going to be made
with the signal scaled pretty small. I'm
going to hit "measure" and I already have
a peak-to-peak measurement going on, and
I want to turn on statistics. And I'm
going to display those statistics and
we're going to let those measurements
run a little bit. So we've waited about 45
seconds and you can see that I've run
just around 50,000 measurements and my
standard deviation of this measurement
is 32.3 millivolts peak-to-peak so
that's how much my measurement is
varying over time. I see a lot of
engineers scaling their signals half-size
on the screen, especially if they're
using two signals, they want to stack
them on top of each other.
Let's see what happens if I make that
measurement on the signal that's scaled to
full screen. So I'm going to hide the
statistics for now. I'm going to scale
the signal to full screen, and I can
actually fine tune that scaling by
tapping in the knob and I get this
little fine
vernier window. And now I have my signal
scaled full screen. Let's turn my
statistics back on and reset them, and
we're going to run another 50,000
or so measurements.
Another cool thing on these scopes that
I'll show off while we're getting to 50,000
measurements. You can actually make
these windows
transparent so that way you can see the
signal underneath your measurement
window. So we've hit about 50,000
measurements. I'm going to go ahead and
stop the acquisition and we can see that
my standard deviation of that
measurement is now 15 millivolts. So the
standard deviation of that measurement,
meaning how accurate
was my measurement over those 50,000
acquisitions, is now half of what it was
when my signal was scaled halfway on the
screen.
That's because when you scale the signal
smaller, you're not taking advantage of
the full eight bits of the ADC on the
scope. I should also say that the bits of
resolution of your scope aren't the only
way to get measurement accuracy. So just
because one scope has more bits of
resolution than another doesn't mean
it's actually going to be more accurate.
You have to consider things like noise
floor and signal integrity throughout the
design of the scope. If you want to learn
more about how to make better
measurements with your oscilloscope,
check out the video "How to Make Great
Oscilloscope Measurements" which was part
of our Keysight Oscilloscopes webcast
series. It's on our youtube channel. There's a
link for that in the description. So
let's draw some scope winners. The first
two names I call are going to be the
4000 X-Series scopes and the next six
are going to be for 1000 X-Series
scopes. So our 4000 X-Series winners are
John Butler and Robert Burgus and then
our 1000x Series winners are Karim Hafez,
Stefania Wolska, Jacob Crawford,
Michael Mineart, Dave Heiser, and Say Luc.
Congratulations! We'll be in touch
with you shortly. Thanks for watching and
make sure you tune in to our live cast
on Monday. You can actually go to our
channel page and hit "get a reminder" for
that and youtube will notify you when
that live stream begins. We also have our
next Find Daniel scavenger hunt
beginning next week. So if you can find
the cut out by Tuesday at midnight, we'll
give away an extra five scopes next week.
And while you're here, go check out some
of the webcasts on our youtube channel.
We have a whole playlist of those. The
link for that is in the description. Make
sure you subscribe to the Keysight
Oscilloscopes youtube page. You can also
follow us on Facebook, Twitter, and
Instagram. Have a good weekend! I'll see
you on Monday!
Alright that's that. It's the weekend.
Time to go home...