RoadTest: RoadTest the Keysight U1282A Digital Multimeter
Author: michaelwylie
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?: N/A
What were the biggest problems encountered?: The physical size of the multimeter.
Detailed Review:
Introduction
The Keysight U1282A is expensive and huge for a multimeter … but I love it. My initial reaction to the device was poor. I couldn’t believe how big this thing was, and I was mad at the fact I couldn’t manipulate the front dial with one hand while holding a probe in the other. However, as I became more familiar with the unit, I’d realized that I was comparing standard multimeters with the Keysight meter. In hindsight, I think it is slightly misleading to call this a multimeter since it’s so much more than you’d expect in one. Hopefully in the following review I can impress upon you my reactions and feelings about this meter. Let’s begin.
The Meter
Figure 1 shows the Keysight U1282A alongside a Fluke 117 and an Extech 410. It’s clear the U1282A is by far the largest of the three. It’s quite clear just by feeling the meter and the probes that they are durable and of high quality. The probes are shown in figure 2.
Figure 1: The Keysight U1282A next to a Fluke 117 and an Extech 410.
One thing that drives me bonkers when it comes to multimeter probes is a dull tip. When working with printed circuit boards (PCBs), the probe tip needs to dig into the pin/pad. This improves the contact between the pad/pin and the probe, as sometimes a small amount of residual flux is left on the board from manufacturing. Some oxidation may also block the probe from making good contact. If you’ve ever probed a circuit board, you’ll understand this frustration – measure a power pin and read 0V, move the probe slightly and read 5V. The sharp probe tip also reduces the chances of shorting because the probe is less likely to slip off the pin/pad. The U1282A comes with really nice, sharp probes. These things hurt when I poked them with my finger, which is exactly what I want!
Figure 2: The Keysight probes and logger cable.
Figure 2 also shows the batteries that came with the unit and the data logger cable. I’ve had a beef about multimeters using 9 Volt batteries for a long time. Most people don’t keep spare 9 Volt batteries around, because a very limited number of items actually use them. I don’t know how many times I’ve stolen the 9 Volt battery from my smoke alarm for a few minutes to take a voltage reading. The U1282A uses 4 AA batteries -> Love it. Finally I have a decent chance of finding spares in my house. Figure 3 shows the battery and fuse compartments of the U1282A. Rubber gaskets seal the compartments from dust and water penetration. Figure 4 shows the printed circuit board (PCB) for the U1282A. You can see the correlation between Figure 3 and Figure 4. The battery compartment connector is on the bottom left (red and black wire) and the fuse with fuse holders can be seen in Figure 4.
I’m always pleased when I see a circuit board like that in Figure 4. It looks like a mess, but it actually shows me that a lot of work was put into this layout. It usually means it’s been designed for performance; each component is laid out to minimize trace length, and thus parasitics. A good PCB design should limit the effect the PCB has on circuit performance. Of course, the downside to such a design can be heat dissipation issues, but I didn’t spot any high power components.
Figure 3: Examining the battery and fuse compartments.
Figure 4: You can’t give an engineer something electronic and not expect them to open it. Here the printed circuit board (PCB) for the U1282A is shown.
Logging Capability
When I first applied for this RoadTest, I really didn’t have an interest in the data logging capabilities of the unit. I was most interested in the waterproof and dustproof ratings (addressed later). Usually throughout my day some ideas pop into my head, but the length of time it would take to actually do them would not be productive at work. At home I would have no logger, so any measurement would be done manually. For example I saw a graph with a capacitor value varying with temperature, and it occurred to me I could examine this now. I put a 10 uF tantalum cap in my freezer, and sometime later took it out to log its capacitance as it warmed. The freezer temperature was measured using the U1282A with a thermocouple as -20°C. The capacitor was removed from the freezer and placed into a room at 20°C. The U1282A was hooked to my laptop and the capacitance value was recorded every second while the capacitor warmed. Figure 3 shows the result. It would appear that the capacitor has warmed after about 150 seconds.
Figure 5: Temperature effect on the value of a 10 uF tantalum capacitor. The capacitor was placed in -20°C and left for a period of time. The capacitor was then placed in a room at 20°C and a data point was taken every 1 second.
I did the exact same test with a 1 nF ceramic capacitor, but there was no variance. Either the capacitance didn’t change with temperature, or the capacitor was so small that it warmed to room temperature almost immediately. I’m inclined to believe the latter. I also had an idea to hook up five, 50 Ω resistors in parallel (10 Ω) and monitor the resistance with the logger. I expected the result to be a line about 10 ohms within 1 ohm. The result is shown in Figure 4. This result was surprising to me, since the temperature only varied by 0.5°C during the acquisition. The jumps are not large, but it was surprising to see very quick changes occurring instead of more gradual trends.
Figure 6: Monitoring 5, 50Ω resistors in parallel for over an hour. The temperature varied 0.5°C during the acquisition.
And finally, I’ve always wanted to monitor my own battery discharge, which I can do with the U1282A! I setup an alkaline cell to discharge and left the logger running. Unfortunately, the computer went into sleep mode after a few hours and the battery discharged a bit before I noticed. However, once I noticed I was able to wake the computer up and the logging continued. Figure 5 shows the discharge curve I measured. It’s simply a classic discharge curve, minus the sudden jump from the computer going to sleep.
Figure 7: Discharging an alkaline cell. The sudden jump is the result of a laptop going into sleep mode.
Waterproof Testing
Waterproof testing was pretty uneventful. The meter performed to expectations. The neatest thing about this part of the testing was discovering the U1282A is buoyant!. It was just odd looking at the meter floating in the water, and having to push it down to submerge it.
Video 1: Waterproof testing the U1282A
Drop Testing
For the drop testing, I thought I would involve my 2 ½ year old son. We grabbed a step ladder and the meter. Also, I’ve noticed testing like this is usually done without the probes attached, but that’s unrealistic. If I’m going to drop this thing, it’s going to have the probes attached. For this reason, we kept the probes attached. Here is a two minute video detailing our fun. Note, I did warn him this was a special circumstance and that he could not drop anything else like this. He obeyed, and has yet to destroy anything.
Video 2: Drop Testing the U1282A. Dropping on cement and rocks with the probes attached, and examining the results afterwards.
Dust-proof Testing
I took this meter on a borehole seismic survey as part of my regular day-to-day job. Surveys are usually smelly, dirty, muddy, greasy, loud, confusing, and a lot of hours. The survey hadn't even started and I was called out to look at a generator. A three phase generator was ordered that could also output single phase. The spooler we have is single phase, high current, but the spooler would not run when hooked up to this generator. The spooler has a line of sensors on it that go into the ground, so it's very important that it works. Figure 8 shows the generator in question. You can see the Keysight U1282A on the left side of the photo.
Figure 8: 3 phase and single phase output generator.
After probing the output the meter read 0 Volts, which immediately makes me think a breaker or switch has been shut off. However, it turns out this generator's single phase output is variable. That is, it can be scaled from 0 Volts to 260 Volts. So, we had to find the dial that scaled the output, and set it to 240V. Figure 9 shows the meter reading after setting the output appropriately. Note, the high voltage indicator on the LCD is enabled to show the user high voltage is present.
Figure 9: The U1282A measuring the generator single phase output.
The slideshow below shows the shape the U1282A was in after I took it to the field. I opened the meter after returning from the survey and no dust had penetrated the design, it was as clean as the day I first opened the unit. The LCD got scratched though, which is unfortunate but only cosmetic. Maybe a scratch resistant coating on the LCD would help? As I write this, I am on my way back to the same survey to perform some field maintenance. If anything changes about the meter, I'll update this post.
| {gallery} Dusty Environment |
|---|
|
|
|
|
|
 |
 |
 |
 |
 |
Summary
This meter is fantastic, and it has become my favorite piece of kit I have. I've only scratched the surface of what this meter can do with my review, but I had to stop somewhere. I hope you enjoyed reading as much as I enjoyed using this meter. Until next time...
