RoadTest: Keysight U1461A Insulation Resistance Tester
Author: waelect
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?: Keysight U1242B, Protel 506 and numerous PAT machines through external application videos.
What were the biggest problems encountered?: The most difficult aspect was the Bluetooth connectivity. Later though finding that earlier Bluetooth dongle provided unreliable connectivity. After purchasing a new dongle all worked really well. Another issue was old firmware in the meter was very old version or appeared to be that way. It wasn't till the end of the test that I was able to update the firmware and fix the issue of the Menu 11.
Detailed Review:
First I would like to thank Keysight and Element14 for the opportunity to road-test the Keysight U1461A Insulation Multimeter. A multimeter is one of the most important tool in any technician’s or engineers equipment and the Keysight U1461A is in my opinion one of the most important meters to break a small barrier that has existed between electrical and electronics trades and engineering. The reason, the U1461A incorporates metering that is found in both electronic and electrical systems, combining both makes this meter a leader in a range of essential test equipment.
This Road-test for myself took on an intuitive approach in the method of reviewing taking little instruction for the Internet where possible unless learning new functions.
The Keysight U1461A insulation Multimeter, I originally thought was a number of individual components ordered, but was surprised and pleased to see the package and all the components nicely packed into a moderate sized portable hard carry case.
Internally the case is well laid out with a sturdy tight fitting pocket for the meter, positive clips to hold the test probes and 2 compartments to house all the leads and accessories. For the meters that in the past I have owned and used I have never seen this level of equipment housing, although it is difficult to know all the manufacturers and what is available.
The lead and accessories are made of good quality material although I did find the case looked very similar to that available in some low cost power tools. The case is a nice thought, I think that Keysight could consider a special case they can call their own. As an example in one of my hobbies; Woodwork, a manufacturer of similar stature to Keysight created a case proform suitable for all their range of tools and with only a very small variations the case can be adapted to use in their entire range. The advantage I have seen is that FestoolTM have an extensive range where clients prefer to use due to ease and consistency to store both in the shop and in mobile environment. Implementation by Keysight would encourage companies, technicians and engineers to purchase just a single manufacturer for all their equipment.
As expected from Keysight I am suitably happy by the construction of the meter and the associated components that have come with the meter. The meter has a strong robust solid feel, a rotary switch has a good positive action and terminals also have the appearance of high professionalism the buttons are easy to touch and to activate any function, although the rubber shield is a little bit difficult at times to get off but I would excuse that as it would play an important role in the IP 67 rating.
I would though take a little bit more consideration in labelling the battery compartment and the fuse holder compartment as there is no intuitive way of replacing the batteries. Battery replacement in most meter are located in the lower part, while the U1461A is in the mid-section. This though is an extremely minor issue.
All the leads a very well made using highly flexible silicon leads the Electrical Resistance test leads are also quite thick though flexible, the probe handles also look appealing and have a comfortable group and the alligator clips look very strong and appear reliable.
The temperature probes is of standard construction and have specific requirements which are very hard to modify or differentiate from other probes the temperature probe interface plug though is that of really good strong solid construction. The probe adaptor though is very nicely constructed, compared with another probes the Keysight adaptor is far superior in build quality.
There are 2 sets of measurement probes supplied, although not sure why. A simple multifunction probe would be better. It is possible that a manufacture could not make one that is detachable. The multifunction probe is in a better alternative, although have not heard from anyone regarding advantage to separate probes.
For obvious reasons switching on if the first thing you would do almost meters the first thing that happens is the loud beep, but I feel that there needs to be a bit more variation in the beep as it can be a little bit distracting. I would like to see a further set up configuration that would reduce the level of their beep a bit more, although still have the option for a loud beep especially good for noisy environments and hearing loss.
Apart from that the visual display is extremely nice with really good high contrast although low level backlight does lose quite a significant amount of contrast but this is possibly a feature of the OLED display that may not be able to be resolved.
The display seems quite chunky with fairly low resolution and I find this becomes comfortable at approximately 500 mm and further away up close it is easy to see the jagged edges of the text. I am unsure of the quality of OLED displays and how much possible variations are available. After four weeks of operation the OLED display has been performing better than my current Agilent U1242B LCD multimeter purely from the contrast aspect.
Starting from the Rotary switch from the leftmost operation leading through to the right-hand most operation I will describe and evaluate the performance of each of the ranges.
One of the first tests is the low current operation in DC mode. Easy to evaluate although was unable to carry out accuracy.
Both the number of counts and the resolution available is surprising for such variety meter like this one. In the evaluation I did not have access to a good strong current source, instead I graphed a single resistance and rising voltage to determine the linearity of the current reading. With the results graphed I found that the linearity of the current range is extremely good as I would expect from a high-class meter like this one. It was this test that it was decided to consider purchasing a test standard.
This one had taken me by surprise as most multimeter is that I have ever used have a single voltage range to measure. On this meter I have found three voltage ranges in this range I carried out a similar test where I was able to also the resistance in a linear progression to check the linearity of the millivolt range. As expected that two had a surprisingly good linearity across a range of voltages. Although a limitation was seen in the microvolts range and noise became an issue.
Initially this one had confused me the most, there are two voltage ranges although they are slightly different I am unsure the reason for it. The first AC/DC voltage range includes an automatic detection of AC or DC voltage but in my road test review I was not able to get a reliable detection of either (A firmware update has resolved this). It appears to me that the Ranges have been separated differences between voltages in electronics industry with a voltage in the electrical industry. Separate ranges is not a problem only noticed as unusual.
The second range includes a “Low Pass Filter” LPF, an essential function great for the electrical industry where variable voltage and frequency sources are used for motor control removing potential spurious voltage affecting the reading. Increasing though electronics are using motor more especially in the robotics industry and this could be a possible range in use.
This range gave me the impression of a sophisticated function, one especially, the ability to measure cable length.
Resistance EB – Called Electrical Bond Resistance range uses a 4 wire method where the sense wire is located inside the meter. Due to the measure of high current wiring, the need for external sense wire is negligible and will not have a big impact on measurements. Using this for microelectronics may place a small inaccuracy but to what degree is unsure.
This range though is very important in communication electronics as well as any system that requires good earthing. In my past work in video security this would also play an import role in performance in large scale operation where potential induced voltage can be present.
Another good application is Audio induction Loop System where copper foil or wire is placed in a room providing high current path as much as 50 Amps peak audio signal current. For this low resistance cabling is essential for good electro-magnetic performance. This meter could easily provide an accurate cable resistance check to get the 0.5 to 2ohm resistance required for effective loop currents with trans-conductance and current amplifiers.
Electrical Insulation Resistance settings - This meter originally when I received it was a feature that I liked and felt that I could use in some of the applications that I have already mentioned. But it was after realising the other functions in the multimeter I now consider this as a primary meter not only for electrical resistance insulation but also a complete service technician meter. The insulation resistance is an excellent method for preventative maintenance in many areas not only electrical but it also in many other communication cabling systems. The performance of the electrical resistance test is was much more important than I ever thought, with extra function too numerous to test in my time frame available. More test will be carried out in the future and presented as they come into play.
“Keysight Handheld Meter Logger Software”
This application is surprisingly effective and creates an efficiency as no other. With the ability to be able to graphically represent the data that is received over time in the method to visually identify problems within such a short period of time. The quick example of this is the dishwasher test that I carried out and described in the next section. From this I was able to determine that the heater appears to be functioning but it switching is restricted and is not turning on at the right times. Combined with another symptom of the problem the timing of the washing cycles, I was able to determine the next course of inspection to determine what the problem is, the control board.
This application will be so beneficial for work not only on the bench but also on the field and will reduce the amount of diagnostics time being I will to use humans visual perception to identify problems. Along with laptop and PC software, I was also happy to evaluate the android software solution and was pleasantly surprised. The only thing that I would highly recommend a Keysight carry out is to update the software to incorporate the Personal Appliance Testing feature of the meter. With the PAT implementation on the android devices and this will be in my opinion the most compact and comprehensive PAT device on the market that I am aware of.
The software has different modes of operation depending on the test that are being carried out. These tests are
Meter Mode-
A simple graphical metering mode which shows a very large screen view of the current measurement seen by the test equipment. The benefit of this would be to be old to observe records immediately available from a distance. This clearly shows the range in which the meter is selected and provides a large text display of the current indication.
Graphical Mode-
In this mode it provides a graphical representation of the charter that is being seen over time. Also clearly visible from a distance this provides a good representation of the data spread over a period of time Which can be beneficial to determine problems while other work is being carried out. For me personally I would use this range when there is no actual urgency in receiving specific data in an instant. I would then be able to allow the the measurement to carry on and occasionally peer over when I have a moment to inspect the progress of tests being carried out. With accurate timing it is possible then to be able to look back on the data and suggest where a problem might exist.
Data Mode-
In this mode it just displays the data that would also be graphed out in the graphical mode. The data will be able to provide just an indication of timed events and actual readings instead of the visual representation of an approximate reading. This would be a feature that I would least use but it would still be used at some stages if needed to find out accurate data at specific times when required.
PAT Mode-
This feature surprised me the most as I was not aware of the fullness of the testing procedure. In this mode it provides a reporting function where the data be collated and stored in such a way that would create the most efficient method of storing and using the data for the future. As mentioned above in the first paragraph this mode of testing is only available in the PC software at the time of writing this review. But I have contacted Keysight and requested that this feature should also be present in Android and Apple operating system. The key benefit of mobile environment is the portability of software and its advantage when on field maintenance trips. The image below shows the basic layout of the electrical appliance testing procedure and has a clear indication of which test setting is required to be set. Finally the software is able on a single click provide a comprehensive detailed reporting system that can be easily printed out signed and dated with all data collected imported into the form automatically.
Dishwasher – in one of my videos I use the meter to log the temperature changes within a faulty dishwasher that I had at the time. Using the K-Type temperature probe inserted into the dishwasher and ran a complete cycle determined what was happening internally. I have stopped partway through the cycle because he became too obvious that there was a problem and there was no requirement to me to continue the test.
One very interesting observation from this is that the data collected was split into two sections I had to stop the machine halfway through the test then restart it. I also stopped logging at the same time. I was concerned at the time when I stopped logging that I would not get a complete graphical representation of the dice that I have collected over the two runs.
Although the graphical plot could not be shown within the software that I am aware of, I was able to extract the data from the results and was able to implement the entire readings from both sets of data without stitching the data together. It appeared that the data was automatically stitched together as a single entry when I imported into an excel spreadsheet. This saves any messing around that I would find when receiving two sets of data in a test. This was not intentional but it was an accidental discovery which was one of the really good features of the software data collection.
I plan to use the meter more in diagnosing any future problems with the dishwasher after this review.
MOV test –
One more immediate and obvious test was the measurement of Metal Oxide Varistors (MOV's). These components are primarily used for protection of power circuits in both electrical and electronic applications and before I received the meter I had a power supply that had failed violently where the switching transistor had blown no apparent reason. Initially I wondered for the cause of this as there was no apparent reason for this component to fail, only to realise that the only possible cause problem was an initial surge current in my power system. The MOV was the only discernible cause of the failure.
I had removed the MOV prior to receiving the meter and after looking at the insulation resistance capabilities I realise that of can be tested up to 1000 volt’s using the meter.
Not only could test the MOV using single measurement with the insulation resistance test I can also use a internal ramp voltage be obtained where they stepped voltage from the meter ramped up to 1000 V or dependent on the mega range selected. As the current is limited up to a maximum of 1.5 mA, this would ensure a safe testing of the MOV.
What I also found during this test is to see the current of the component stay steady very low till it reached its clamping voltage where it very quickly rose until it hit the trip current.The only disadvantage that I found for a good visual representation of the clamping, is that the software had no ability to display a nice graph curve of the clamping voltage vs current for the MOV.
The video of the test is below.
I have since this test contacted Keysight and asked them if a graphical representation of the ramp function can be implemented in the software which can provide an accurate response curve for the components that are tested in this range.
It is this feature that had won me for more than just an electrical application. For most people when they see an insulation multimeter there is an automatic association with the Electrical trades. And that many electronics applications are simply and ignored. I have essentially applied functions that make this multimeter almost essential for any tradespeople or engineers in both electrical and electronics industry.
The user guide also states that other protection devices can be tested including gas arresters and more.
This meter is in my opinion an exceptional meter and exposed a number of useful elements that would have I would have overlooked if I was looking for my next meter. With the information that I have gathered so far I would highly recommend this meter is an excellent preventative maintenance and service technicians meter for both the electrical and electronics industry. For preventative maintenance this tool is so small that it allows an extremely portable environment in preventative maintenance where in some cases the need for tools on site can be awkward to carry around. This meter with some added mobile software modifications could increase its appeal. This meter packs a big punch catering for so many aspects and tests that can be done.
