RoadTest: Agilent 34461A Digital Multimeter
Author: migration.user
Creation date:
Evaluation Type: Independent Products
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: Fluke 8845A Fluke 8846A Keithley 2000 Rigol DM3068 Tektronix 4050
What were the biggest problems encountered?: Poor support for Mac users.
Detailed Review:
Primary Market
Professional electronic engineers, precision electrical test and monitoring
Secondary Market Opportunity
Home hobbyist, hackers, makers
Fluke 8845A
Fluke 8846A
Keithley 2000
Rigol DM3068
Tektronix 4050
The Agilent 34461A Truevolt Digital Multimeter, a 6 ½ digit replacement for the venerable 34401A DMM, certainly lives up to it’s heritage, providing benchmark reliability and accuracy consistent with the 34401A legacy.
In this review I’ll discuss the numerous features offered by the 34461A bench top multimeter, but not from a technical perspective – rather through the lens of an electronic hobbyist / hacker / maker and what those features mean for my usage.
If you’d like to dive into the technical aspects of the multimeter, there is plenty of information available on Agilent’s website.
I would also recommend the video review by Dave Jones of the EEVBlog. It’s bloody awesome and his feedback is anything but negative. He has a tear down video as well.
Now, before I get into the details of this road test, the real question is would I recommend that you buy an Agilent 34461A?
The answer is … it depends. After all, it’s a question of value, and only you can determine if the value of the 34461A outweighs the US $1,050 cost. To answer that question personally, I would say that yes, I would recommend getting the 34461A… In fact, I’d like to get another one at some point.
The biggest reason I’d recommend the Agilent to a serious hobbyist is the confidence it provides. As a hobbyist, I’m in a constant state of learning. As I try new things, I need to have confidence that the measurements I’m taking are accurate so that when things (typically) don’t turn out as expected, I know that it’s the circuit that needs tweaking and not my multimeter. Additionally, as my experience has grown, so too has the importance of smaller and smaller measurements. Before receiving the 34461A I was using an Agilent U1232A handheld digital multimeter, and while I’ve been very happy with it’s performance, its resolution (or that of most handheld meters) just can’t match the 6 ½ digits of the 34461A. Not that the U1232A doesn’t have a valuable place on my bench, I have found throughout this testing process that the meters compliment each other very well. The only flaw in the U1232A has to do with a gap in current measurement, but happily that’s no longer an issue.
In addition to the confidence I have in the readings of the 34461A, and its resolution, the graphical and statistical features have proved extremely valuable (particularly as my oscilloscope is of the crusty variety). I’ll detail these more fully in the sections that follow, but using them has not only saved me a tremendous amount of time and headache, but also given me a better understanding of what’s going on within my designs.
I’ll mention one more thing before moving into the details of the road test. The fact that the 34461A is a drop-in replacement for the 34401A with full SCPI compatibility is I’m sure very important for all the professional electronic engineers out there… but it has absolutely no importance to me, or I suspect most hobbyists, so I’m not going to talk about that feature.
Getting the Agilent 34461A DMM set up was as simple as taking it out of the box and plugging it in. The multimeter came well packaged, if a bit no-frills, and complete with accessories and calibration certificate. The most challenging part of the process was putting the RJ-45 connectors on the network cable so that I could reach a network jack (connectors and cable not included).
In evaluating the Agilent 34461A digital multimeter, I purposefully did not review any of the production documentation so that I could obtain a true sense of how intuitive the buttons and menu systems were. Before getting into the controls however, I specifically wanted to look at the boot up time as that has been mentioned as an early complaint (taking roughly 50 seconds). It seems Agilent has made some firmware updates because the meter booted and was ready for measurement in less than 30 seconds. I’m not sure why this was a concern as I think an appropriate warm-up time for any test instrument is important, but for those who couldn’t bear to wait almost a full minute, you’ll be happy with the improvement.
To touch briefly on the exterior of the 34461A, no pun intended, the quality of the materials and level of finish are exactly what one would expect from a high-quality instrument. The buttons are a nice solid rubber with a soft feel, the plastic bale is sturdy and supports the meter well, the rubber surround fits well and feels like it would protect the meter from accidental bangs or drops (not that I tested that), and of course the screen really sets this meter apart from others on the market. Additionally, the test leads and included accessories are of excellent quality. The leads have nice silicon wrapped cables that are very flexible. The attachments (mini-grabbers, one hook-type grabber, and the thin needle probes) all fit easily but securely on the ends of the probes and make probing small or tightly packed components much easier. I will note however, it would have been nice to get two hook-type grabbers… I have no idea why Agilent felt that only one was required.
As I began actually using the meter, I’d love to say that nothing tripped me up – however I have to confess that in my excitement to turn it on for the first time I pressed the front / rear terminal selection button and sat there befuddled, wondering why the screen wasn’t coming on. In my defense, the selection button is the most prominent button on the meter (and deceptively “power” looking).
Still excited, yet slightly embarrassed I found the power button on my second attempt and was ready to explore the menu system. Despite my rocky start, navigating the menu system was completely intuitive and I had no issues making adjustments or finding the right button.
Now that the basics are covered, I’ll talk about each feature individually, followed by a look at how the Agilent 34461A stacks up against comparable multimeters like the Fluke 8845A, Fluke 8846A, Keithley 2000, Rigol DM3068 and Tektronix 4050, and then end with my conclusions on the Agilent.
What can I say? Measures like a boss. My only real comment here is relative to current measurement. The meter defaults to measurements on the 3A terminal and you have to push a selection button to move it to the 10A terminal. I’ve learned that it’s always best to start on the higher terminals and then move down once you’ve confirmed the reading is within the appropriate range. So, it would make more sense to me for the default to be the 10A instead of the 3A.
The color graphical display on the 34461A is one of its outstanding features. The competitive products I cover later aren’t even close on this. The numbers are clear and easy to read from all the angles that I used. You can change the blue background to black for higher contrast if you really need it. If you have more than one multimeter, then you can put a label on the screen instead of a post-in note. Overall, it’s a very nice display. The few things that I would have liked to have seen include a dual display feature and better use of the screen real estate (or at least the option to go ‘full screen’ with some features). There actually aren’t too many instances where I think a dual display would be really handy, but measuring voltage as well as frequency would be one of them. Also, as nice as the trend plotting, histogram, and statistics are (in fact, because of how useful they are, more on these in a bit), it would have been great to expand those to the full screen resolution.
I found the probe hold feature of the 34461A extremely useful in testing circuits, particularly when testing over a range of variables (supply voltages, regulated voltages, current loads, etc.). The multimeter allows you to capture up to eight different measurements before new measurements begin overwriting the old. While this didn’t prove a problem in most circumstances, there were a few times I would have liked some extra spaces. This is one of the examples where I think the screen real estate could have been better optimized.
Continuity
Not much to say on the continuity test other than it worked as expected. I did conduct the probe test (seeing how quickly I could generate a continuity reading) and found the results more than satisfactory.
Or rather, lack thereof. Not including a capacitance measurement was fairly surprising to me, as it seems far more useful than some of the other features that were included. The Agilent U1232A meter I have does a good job of measuring capacitance, but I would have loved the resolution and accuracy of the 34461A for this. I’m not sure what would have been required to include a capacitance measurement that met the same quality standards as the rest of the meter, or what that would have done to the units price, so perhaps it was a good call by Agilent from both a business as well as market value perspective not to include it, but still a bit disappointing.
When comparing the 34461A to the U1232A, the U1232A was almost as accurate but with less resolution. However, the largest benefit to me between the bench and handheld DMM is the statistical and display functions of the 34461A DMM. They proved incredibly useful and really stand out as features that make the Agilent 34461A DMM well worth the investment even at the hobbyist level. In particular I used the statistics and trend plot almost constantly (the histogram came in handy as well, but I wasn’t much of a fan of the bar graph).
The limit testing feature works as one would expect, displaying and counting when readings are above or below a specified range. Conceptually I can see how this would be a valuable feature, but I didn’t find an immediate use for my current projects so testing was limited to setting a range and manipulating the input to trigger limits... and it worked quite well.
This is another feature that I was eagerly looking forward to testing. I can say that the biggest lesson I learned when first starting with electronics is that temperature is important! I know, that seems rather basic now, but I imagine beginners focused on Ohm’s Law and manipulating voltage and current often overlook it… I certainly did. Unfortunately, I am unable to test the temperature reading because the unit did not include the temperature probe. Really? On a $1000+ meter, you can’t give me a probe that most likely costs under $10 to manufacture? Of course, they do sell them for around $60 online, and I’m sure I’ll break down and buy one (which means success from a marketing perspective), but this omission was a bit disappointing.
The Agilent 34461A has three methods to capture data: Saving a screen shot to USB or internal memory, saving the data file to USB or memory, or using the LAN connection and included software. The software can also be used to control the multimeter, but I don’t see a practical application of that for a hobbyist, so I didn’t spend much time investigating software control.
Saving a screen shot to USB or memory may be sufficient for one-off circumstances where a small number of samples are required, but for any real data logging you’ll want to use either the data acquisition or software capture methods. Two things that could be improved with the screen shot method are auto-incrementing the default file name, perhaps based upon data and time of capture, and recognizing when a USB is attached and adjusting the default destination accordingly. As it is, it is a cumbersome process to change the name each time you’d like to capture a screen shot (the destination only needs changed once per power on).
Saving data to USB is the roughly the same process as saving a screen shot, but because one would typically do this much less frequently (it captures all the readings into a CSV file), it wasn’t a tedious a process. Still, it would benefit from the same changes. Overall, this method was a very nice change from manually logging data, which admittedly is FAR more tedious than changing file names and directories.
In terms of software access (tested on a Mac via LAN), well let’s just say the experience was less than overwhelming. First of all, Mac’s aren’t supported by the included software, which is really annoying, but not something I haven’t experienced before. By typing the IP address directly into a browser, Mac users can access a web version of the software. I have no idea how this differs from the included software, so perhaps some PC users can weigh in with their thoughts. In any case, you can certainly monitor and even control the multimeter from your computer.
You can also get it to capture the data… into a window with no export feature. I’m afraid it’s cut-n-paste after that, which really confuses me, as the meter itself will export to csv – so how difficult would it have been to include that within the web-based interface? Others with different needs or multiple devices may find the software quite handy, but this limitation effectively made connection via LAN useless for me.
Overall, the software and data capture comes down to the ability to export data to a USB, which the 34461A does very well.
| Keithley 2000 (Tektronix) | Tektronix 4050 identical to the Fluke 8845A | |||
Price | $1050
| $1050
| $1140
| $799
| $1450
|
Dual display |
|
|
|
|
|
Capacitance |
|
|
|
|
|
Display |
|
|
|
|
|
Interface |
|
|
|
|
|
Analysis |
|
|
|
|
|
Accuracy |
|
|
|
|
|
All of the competitors reviewed (by web, I didn’t physically have a chance to use any of these other multimeters) appear to be accurate and quality built machines. The rating system used above is relative to the 34461A (for example, I’m not implying that the Rigol DM3068 is inaccurate, just less accurate than the 34461A). As for display, interface, and analysis functions, all of the other multimeters fell well short of the 34461A.
In conclusion, I’ve been extremely happy with the Agilent 34461A Truevolt DMM, but as a hobbyist the questions I’m concerned with are:
There is no easy answer to the first question. I can say that having one has been valuable to me, not only for its accuracy, resolution, and additional features, but in the way its enabled me to gain a better understanding of the projects I’ve worked on. So the best answer I can give is yes, I would budget a precision bench multimeter into the (always growing) list of parts and equipment I’d like to acquire.
As for the second question, that is much easier to answer. Unless you don’t have an alternative means of capacitive measurement, and perhaps even if you don’t, the Agilent 34461A is clearly a better instrument and a better value than the alternatives. If you’ve been thinking about buying a precision multimeter and came to this review as part of your research, I hope you’ve found it helpful… and just to be clear, I would definitely recommend the Agilent.
