Hi. I'm Mark Bailey. I'm an application engineer here at Agilent Technologies. Today I'd like
to talk to you about optimizing your throughput through test systems and specifically using
the digital multimeter and setting up the multimeter for fastest measurements.
In general, one of the things you can do when you set up a test system is make sure that you
group the different functions together that you're going to be measuring.
By that, I mean if you're going to be measuring a DC voltage measurement and then a current
measurement and maybe a resistance measurement it's a lot better to put those all together.
And take all your DC voltage measurements together then change the volt meter,
make your resistance measurements, and so forth.
This will cut down on the overhead and all the switching that goes on inside of the multimeter.
So, you'll be able to go much faster. But I'd like to talk more specifically about the multimeter.
I have a 34410A. I'm going to talk to you specifically about the five different
things that you can do to speed up the multimeter and make its optimum measurements.
This instrument actually is capable of making 10,000 readings a second. So, we're going
to see if we can get to there. So, let me go ahead and turn to the multimeter itself.
It comes up in an auto-mode with a lot of digits of resolution. It's in auto-range mode
and so forth. We're going to change some of those things.
So, I'm going to do that using the internal web browser that's built into the 34410A.
I've gone ahead and connected to that just through a LAN cable directly to my laptop computer.
So, again everything I'm doing is just using the internal web server thatís
built in to the 34410A.
So, let me go ahead and make some adjustments to the instrument using the laptop.
Okay, so I'm into my control mode on my 34410 using the internal web server and my laptop.
So, first things to notice, the default settings is in DC Volts, it's in auto-range, auto zero
is on, peak measurement is on. It's taking 10 power line cycles to take the measurement
or about 167 milliseconds to take a measurement.
So, if wanted to take 10,000 readings a second which I've set up my sample count, that‚Äôs
going to take forever. So, I notice some things I want to change. One of the first ones to
change is going out of auto-range and going to a fixed range. This is so that my instrument
Doesnít get confused and jump around between ranges which would slow it down.
Internal to the 34410 is something called Peak Meas and it actually is regularly at
50,000 readings a second taking an AC measurement. So, I'm going to turn that off because I donít
want that running in the background, it slows things down. I want to change the integration
time, instead of 167 milliseconds I want to make it go much faster.
So, I'm going to select 0.006 power line cycles which translates actually to 100 microseconds.
So, theoretically it can go 10,000 readings a second. However, I also have auto zero on.
Auto zero takes a measurement of the input and it takes a measurement of an internal short
and it goes back and forth, back and forth.
This gives you a really accurate measurement but because I'm taking a burst of measurements
over a one second period I'm not going to worry much about drift and so forth. But actually
before I change that let me go ahead and apply this and show you the problem with auto zero
on.
Go ahead and start a measurement. It actually beeps at me because it can't do it as fast
as I want it to do. And then, you'll notice it takes about six or seven seconds for it
to get the measurement made. Now, I'm going to go ahead and turn auto zero off,
apply that to the instrument. Start a measurement again and you'll notice it's a whole lot faster.
Okay. It took like one second to take my measurement that time. Okay. Now, I supposedly have 10,000
readings in storage. Let's take a look. I'm going to want to look at all 10,000 of them.
So, I punch in 10,000 for the number of readings to get and I go ahead and get the data from
the internal memory. And sure enough, it turns out there's 10,000 readings there.
Okay. I can capture those readings by doing a control A to get them. A control C to copy
them and I drop them into my Excel spreadsheet. I paste the readings.
There they are and if I now just highlight and plot the measurement itself you'll see that when I do that,
I see the data plotted out that I captured.
Okay. So, we just optimized the 34410 For the fastest possible reading rate.
We turn auto zero off, we've set to a fixed range. We've changed the integration time to a very
low 100 microseconds. We've set trigger delay at zero; we've turned off peak measurements.
And if this was one of the older instruments we could even turn off the display because
sometimes the display being on slows things down.
If on the other hand, you're making AC measurements there's other things to consider.
There's a low pass filter in there thatís typically defaults to 20 Hertz on the 34410.
It can go as low as three Hertz but goes even slower. There's also a 200 Hertz rating. And so, to
get the maximum reading rate out of the AC, you go to the 200 Hertz setting on the AC filter.
So, hopefully this would help you get a higher throughput through your digital multimeter.
Thanks for listening and I hope you learned something out of this.