RoadTest the Keysight U1282A Digital Multimeter - Review

Table of contents

RoadTest: RoadTest the Keysight U1282A Digital Multimeter

Author: Former Member

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?:

What were the biggest problems encountered?:

Detailed Review:

Received package


First of all, a big thanks to Element14 and Keysight for giving me the opportunity to test this Keysight U1282A multimeter.

Here is the content of the package I received:



So I got the standard Keysight U1282A package including:

  • the U1282A multimeter
  • a set of probes
  • a U1173B USB/IR interface
  • 4 AA batteries
  • a quick start guide

And I also got the optional U5404A remote switch probe and adapter (on the right of the picture).


First impressions


First of all, when taking the multimeter in hands, it feels a bit big and slightly heavy, but it also feels like great quality materials and construction, and very rugged. And this quality impression only grows when opening the battery compartment to insert the provided AA batteries. It has threaded brass inserts and captive screws, and a very nice rubber gasket.



The range switch feels very solid and easy to take in hand, but rotating it requires a bit more force than what I'm used to on various other multimeters. Thankfully, the tilting bail is very strong, so when the multimeter is tilted, is doesn't move at all even when applying the necessary force to switch range.


The screen shows big digits which are very readable, even from an angle. It shows many information so that you always know exactly what you are measuring, in which mode, in which range, etc... Its fast update rate makes it feel very responsive, and its bar-graph helps seeing trends or very fast changing values.


In low light conditions, the back-light works a treat to keep the screen perfectly readable with its evenly distributed amber light.



The standard probes also feels like good quality, but cables could be a bit more soft, they are definitely not silicon cables. The probes seems most appropriate for heavy duty testing on mains electricity panels, but not the best for low power electronic board probing, where I would use some slightly less bulky probes with slight shorter and sharper tips, with no CAT IV protection caps.


The U5404A remote switch probe is also of very good quality. Its cable is quite thick but feels softer than the standard probes one. The probe is bulky which also makes it mostly appropriate for heavy duty mains probing.



The quick start guide looks big, but it contains 11 languages, so in the end, there is less than 30 pages for each language. It is mostly pictures of how to setup the multimeter, probes and DUT for all the various kinds of measurements. It is clear and simple, but I would guess that most people buying such a class of multimeter already knows pretty much everything in this quick start guide. For more advanced usage, you should download the full user's guide on Keysight's website (U1281-90003).


Firmware upgrade


My U1282A came with firmware 1.01 installed. Keysight has an updated version available fixing some issues, so I'd rather update my multimeter to the laster version before spending time testing all the features.


The firmware update software is only available for Windows, so I had to use a Windows VM to get this done under Linux.


The update procedure was simple and went totally smooth:

  1. install the PL2303 driver
  2. install the firmware update software
  3. plug the multimeter on the computer using the USB/IR cable
  4. turn the multimeter on
  5. launch the firmware update software and let it auto-detect the multimeter                                                                                   image
  6. just click 'Upload firmware' and wait for about 2 minutes                                                                                                              image
  7. the multimeter will reboot itself on the new firmware                                                                                                            


Basic usage


I expect that anybody who buy such a high range multimeter will already have at least some experience using a multimeter, so I won't explain how the basic features are used or what they are for. I will rather give my feeling about those standard features compared to the experience I have with cheaper multimeters.



The first feeling when measuring voltages (either AC or DC) is the increased resolution (60000 counts) compared to cheaper meters. You get one more digit than with most cheap meter. For very low voltages, you can use the mV range which will give a 1 µV resolution for voltages below 60 mV. The fast refresh rate of the display and the bar-graph also gives a great feeling of reactivity while still staying perfectly readable.


The next great thing is the dual display. By default, the secondary display will show the temperature, but it can be switched to display the line frequency while the main display show the line voltage. You can also show both AC and DC components of the voltage at the same time.


For those working in industrial environment, especially around motors and Variable Frequency Drives, you will probably enjoy the Low Pass Filter that can be enabled for voltages measurements.


Another thing to note is the hazardous voltage indicator that will appear as soon as the measured voltage goes above 30 V (lightning symbol).


And one last thing to note is that the multimeter will beep and display an error if a test lead is connected to the wrong terminal (A or µ.mA) while trying to measure voltage, which can prevent you from shorting the power source you want to measure.


Overall, it is full of features and pleasant to use. A very good start !



The current measurement feels quite similar to the voltage measurement. Lots of features, and a great resolution. It can measure up to 20 A for 30 seconds, or up to 10 A continuously, and it can

go down to a µA range with a resolution of 10 nA which will be great for testing very low power embedded electronics.


The dual display can be used to show a combination of AC, DC or AC+DC current. It can also show the AC line frequency and in the mA range, it can also show the current as a percentage, either in the 4-20mA range or 0-20mA range, which is useful to measure various kind of industrial sensors using current loop.


When setting the range switch to current measurement, it will also beep if the test lead is not connected correctly, but the logic is the opposite compared to the voltage range. Instead of checking if a test lead is connected in the wrong jack, it checks if a test lead is actually connected to the correct jack. So if you turn on the multimeter in the Amp range with no lead connected at all, it will beep. This might be a bit annoying if you are used to first turn on your multimeter, set it up, and then connect the lead. But anyway, it can still help to prevent some mistake.


Continuity testing

Maybe the simplest, but also one of the most used feature of a multimeter is the continuity testing. And the U1282A does not disappoint here. It is very fast, latched, and the little bonus here is the red LED at the top of the multimeter which lights on when detecting continuity. This can certainly help in a very noisy environment.

Note that the v1.03 firmware is needed to get a responsive LED feedback.


One thing that I was not used to is that it is possible to change the manual range even in continuity mode, and this modifies the continuity threshold. By default, it is set to 600 Ω manual range which has a continuity threshold of about 25 Ω, but you can manual range to 60 Ω to get the threshold down to about 5 Ω or you can manual range up to 600 MΩ to get a threshold as high as 109 kΩ. I can imagine this to be useful in some specific situations.



Resistance measurement cover a quite wide range from a 1 mΩ resolution (in 60 Ω range) up to a 600 MΩ range. That's wider than any handheld multimeter I've tried.


Unfortunately, resistance measurement felt a bit slow, so I gave it a quick comparison with other meters around. And indeed, when measuring low resistance, most meters take between 1 and 2 seconds to auto range for MΩ down to Ω, while the U1282A takes around 3 seconds. Nothing really major, but just enough to feel it. Anyway, I guess this is the price to pay to have such a wide supported range. And to be very clear, this is only the auto ranging process that is a bit slow. Once you are in a specific range (either manual ranging or continuous measurement of similar value) the display refresh is still very fast.


Note that for very high resistance measurement, there is also a conductance manual "range" that can measure down to a resolution of 0.01 nS which is equivalent to 100 GΩ !



A few things to note about the capacitance measurement. First of all, we get "only" 10000 counts in this function (compared to the 60000 counts in all other functions). The lowest range (10 nF) gives a resolution of 1 pF which should be more than enough for almost any usage.


Measuring small caps is as pleasant as using other functions. You still get the high precision, high stability and a fast reading. But when measuring high value caps, the auto-ranging starts getting annoyingly slow. With a 1500 µF cap, auto-ranging takes about 22 seconds (a few other meters all took less than 10 seconds). So if you want to measure a whole bunch of big caps, you will definitely want to manual range, which brings measurement of my 1500 µF cap down to 4 seconds. So this slow auto-ranging is not really a big deal as it is easy to workaround in a still very usable way, but nevertheless, it would have been even nicer with a faster auto-ranging.


So this is a small disappointment here for me, even though I know it won't really be an issue for my own usage.



Diode measurement works just as expected, with a few nice touches. It can measure forward bias up to 3.1 V so it lights LEDs without any issue, including white LEDs. It will give a continuous beep for a shorted junction (which is quite common), and it will also give a short beep when measuring a normal diode junction (around 0.6 V). And it does all of this in a very responsive way.


Diode measurement is just perfect for me.



The U1282A also support temperature measurement using either a K-type of J-type thermocouple. Unfortunately, the multimeter does not come with a probe, but arguably, the probe you need will depend on the type of medium you want to measure (liquid, air, flat surface...). Still, it would have been a nice touch to provide a simple bead type thermocouple such as the U1186A along with the multimeter.

Anyway, the multimeter gives an impression of very fast response to temperature variation. It can display either °C or °F and has a 0.1° resolution. Simple and efficient.


Note that this multimeter only supports one thermocouple, unlike some other models such as the U1242C which supports dual thermocouples with differential measurement.


Frequency counter

This multimeter is also able to act as a simple frequency counter, up to 100 MHz. It can be useful in many kind of situations. For example, you can check quickly that a crystal is oscillating properly at its designed frequency. Note that you can choose between two division factors, either 1 (default) or 100. With the first one, the counter will pick-up very low frequencies, up to 10 MHz. With the second one, it won't pick-up anything below 1 MHz and will go up to 100 MHz. To check a crystal of a few MHz, you need to manually switch to the 100 MHz mode (using the Range key), to avoid picking-up the 50 Hz hum which prevent reading the crystal frequency.


I have been able to read frequencies up to 40 MHz, but couldn't get a stable reading above that, but it is most likely an issue with the frequency generator I used rather than the meter itself. It would be interesting if someone else could check some frequencies above that.


The meter is also able to display the duty cycle and the pulse width (either high pulse or low pulse), but not in the 100 MHz mode, so only for lower frequencies. This open a whole lot of possibilities in itself... I could use this feature for embedded software development, toggling a GPIO pin when starting doing the main task, and when going back to idle, and using the duty-cycle measurement to check how close my task is to using 100% of the available CPU cycles.


Non-contact voltage detection

The U1282A is also capable of non-contact AC voltage detection with its Vsense function. It has two different ranges; Hi sensitivity or Low sensitivity, which change to the distance from which a field is detected. When an electric field is detected the multimeter will beep and the Vsense red LED with light up.


I found that the difference between Hi and Low sensitivity is a bit small. I would say that Hi sensitivity detects the field about 5 cm further away than Low sensitivity. But what I find really nice with this meter is that the bar-graph is showing the strength of the field with some decent precision. So independently from the beep, you can see whether you are getting closer to the source of the field, which can be great when you know that there is some AC voltage around but that you don't know where it is coming from.


That is definitely not the feature I will use the most, but it is well executed and can surely come in handy once in a while.


Other features (min/max/average, peak, null...)

The U1282A can do min/max recording with true arithmetic average of all readings. It will beep each time a new minimum or maximum is read, and you can cycle the display between Max, Min, Average and current reading. It will also display the duration of the record, and the time at which the minimum and maximum were read. This can be used for example to measure a sensor on a machine. While you are operating the machine, the multimeter will do the record and at the end you can check the minimal and maximal reading of the sensor. This could also be used to measure some consumption, reading the time and average current.


It can also do peak detection. So for example, for mains AC voltage measurement, here I get a maximum of about +325 V and a minimum of about -325 V (for a RMS value of about 237 V). This can give some really useful information when measuring a non-sinusoidal AC voltage. It works the same way as the min/max function, it will beep each time it records a higher (or lower) peak, and you can cycle the display between the Max and Min peak value.


Another quite common feature is the relative measurement. It allows to null out leads resistance when you want to measure some very low resistance, but it also allows to store a reference measurement and show display the difference of new measurement compared to the stored reference. For example, if you have a known good component, you can measure it and store it as the reference, and then test a bunch of identical component and see how much they differ from the known good one. Note that while in relative measurement mode, you can press again the Null key to see the currently stored reference value, which is a nice touch. And you have to press Null a second time to disable the relative measurement.



The U1282A is a very nice multimeter, packed with a lot of features, in a very robust case. Here I've just tested the basic features, but those are the one that will be the most used, and after testing all this, I've got a great feeling of confidence, reactivity, stability and precision.


For my use case, they are only two small details I would like to see improved with this multimeter:

  • The slightly slow auto-ranging in resistance mode (and in capacitance mode but that is less important to me).
  • The lack of function saving when turning the range switch (or at Auto-Power-Off), which mean that after turning on again, I have to setup again the appropriate mode, range, secondary display, etc...


With all these features available, I would highly recommend to any user to actually read the entire user manual, to unlock the full potential of this multimeter. And even after this, it will require some creativity and imagination to discover all the nice things you can do with this multimeter, along with various kind of sensors or some smart software for example.


In some follow-up post, I will try to dig into some more advanced or more esoteric features, I will try to put data logging at good use, and I will try to do some serial communication programming.