Hioki DT4281 Multimeter : Teardown and first impression

[CosPhi]

Hi guys


REVIEWhttps://www.eevblog.com/forum/testgear/hioki-dt4281-multimeter-teardown-and-first-impression/msg601911/#msg601911

I got a new Hioki DT4281 multimeter. Because it was nothing about this meter in the forum I thought I make an short teardown and first impression review. I just used it for two days now, so it is to early for an full review.


When I got the package I was surprised about the weight and size. It is a pretty thick meter. The range switch feels good, probably also because there are not so many switch positions. Usually I like a seperate mV position for DC Volt because faster autoranging and sometimes when you take just a quick look to the meter and read just the number but not mV or V so ... you might think there is some voltage but there are really just some "ghost" millivolts.


I got this meter because Hioki say it would be very fast. And it is really. On V DC it almost makes no difference if the meter does autorange or you set it to the range. Almost the only difference between autorange and manual range is in autorange you see quick the decimal dot move and then it show the voltage right on the first reading. And this shown voltage does not change even one last digit after that. On manual range you get sometimes one reading with a bit lower voltage but the second reading is also then the voltage and it also don't even change one digit after that. This super stable reading right from the beginning is really nice. My other meter the Agilent U1272a is about the same speed in manual range (auto much slower) but the last digit rises about 5 last digits in about 2 seconds. Because autoranging is so fast .. I think I use manual range much lesser than on my Agilent where I often use manual range (and the Hioki comes up from mV).


In AC voltage I think is about the same speed as the Agilent but I think the Hioki is quicker stable when you remove the leads from the voltage.


The contunity tester is very fast. And the dispaly glow red when on the same time it beeps. The nice thing is even you use backlight on the meter the backround color change from white to red.

Anyway the backlight is really a nice one. Also the display at all.


The other functions I did not really test much until now. But as I said on the beginning, I write a larger review after I used the meter a bit a while.

What else ... it has a shutter function and that works very well. The buttons also feel very good. They are surprisingly stiff for an asian product.


The probes have a golden coating on the tips and removable cover to reach Cat. 4. The probes feel very good in the hands. The cable on the probes is soso, there are betters and there more worse cables ... The cable lenght is just 90cm. I think the probes much very good when you use the meter on a bench for work. For me on industrial work, I would prefere a longer cable where I can seperate the probe tip and plug for exaple and aligator clamp on it (like the Agilent probes).



About the teardown ...

The meter is build very solid and it has many layers inside. I was surpised to see no metal shilding at all. Instead it has pretty thick conductive plastic on top under the range switch and on the backside. Even it has metal inserts to make contact, I have no idea about how effective it is. Does have someone experience with it?

I also thought there would be more overvoltage protection, but they made a kind of separate chanel for the overvoltage inside the creme white plastic.

For they don't know, the DT4281 can measure just uA and mA. For people who like measure Amps they have to look at DT4282. But on the DT4281 is an clamp function, where it calculate the voltage from the clamp the an Amp value. Sadly just in AC


If somebody has questions, just ask.

[CosPhi]

more pictures

[CosPhi]

and more

[retiredcaps]

Thanks for sharing the teardown pictures.

Can you post a picture of the LCD digits side by side with a few other known meters so we get a chance to see the font quality and size?

[radhaz]

Thanks for the teardown. You have saved me the trouble of taking mine apart.
It certainly is a quality DMM.

[Lightages]

Now THAT is a well made meter. Too bad they aren't more common.

[retiredcaps]

Now THAT is a well made meter.

At $400 USD, I would expect quality to meet or exceed the top equipment makers.

[Vgkid]

That is a really nice looking meter.

[Wytnucls]

Input protection looks fine to me: current limiting resistor, PTC and sparkgap.
The only downside of the meter I noticed, is the missing bar graph and duty cycle function.
Also, the PC connection hardware is an optional extra.

[jasonlang]

Thanks for sharing the teardown pictures.   I am focused on this Multimeter.


Where is the precision resistor?  Under the LCD display?









 

[CosPhi]

Hi guys

I'm sorry because I didn't answered the questions ... I'm a bit out of time at moment.

 retiredcaps asked for the display. I realized just after that, I did not sent any picture with the display on. The display is an really nice one and absolute nothing to worry about. The backlight is also very bright (almost to bright  ). Kiriakos made a long review about the DT4282 with a lot of pictures included http://www.ittsb.eu/DT4282%20review.html

I agree in most point with him so far.

 jasonlang asked for the precision resistor and what's about behind the display. As you can see I removed the display itself and what's left on the pcb is just the frame with the white backlight and the red alarm light. This frame is soldered direct on the pcb 3 times. Even it's not difficult to desolder that and solder on again I just don't like it to do on a very new meter.

One thing I really like is the Min/Max is always active in background. So when you go to the Min/Max mode the showed minimum or maximum value is not just from when you enter that mode, the value is since you started the measusrement. On other meter you have leave the Min/Max mode to reset the values. On the DT4281 you just push the "clear" button. I like it for two reasons. Sometimes you read a Max value and ... what was it??? Because the Min/Max always work in backround maybe you can get the value back. The other reason is when you measure on a machine something and you like to know the Min or Max value for each cycle,  you just push the "clear" button for each cycle. On other meters often you have to leave and enter the Min/Max mode again.

I don't like how the implemented the current clamp funtion. On the specs is writen the function is for some Hioki clams like all other company also does. Just this meter is for some special clams (3 models) from Hioki. To get a correct reading for my C.A. clamp I have to choose 20A on the meter while I'm on 10mv/A on my clamp (100A/140A range) and 200A on the Meter while on the clamp 1mV/A (1000A/1400A range). So that's not a such big problem .... but ... the meter turn the display red and blinks with 20A when I go over 20Amps     This warning is maybe ok for these Hioki clamps ... but with my clamp I could go much higher.

But that's at moment the only point I really don't like on the meter.

I almost used the meter daily the last two weeks and I really love the stable repetitive reading. So still big 

[CosPhi]

For people from the UK

http://www.testtoolsshop.com/hioki-dt4281_professional-multimeter-providing-efficient-high_precision-measurement-343

A new DT4281 for just £129.00.

[kado]

Thanks CosPhi for sharing your experience and the interesting teardown about this meter.

Since I am looking for a while to buy such a Hioki DT4281 I am very excited seeing your link to a UK seller. But unfortunately they don't sell to Germany, maybe they also only sell to companies?

May I ask whether there is some one in the UK who can buy and send it to me? Of course I have to pay to him before buying / shipping!

73 from Karsten
DL4DAD

[amiq]

Thanks CosPhi for sharing your experience and the interesting teardown about this meter.

Since I am looking for a while to buy such a Hioki DT4281 I am very excited seeing your link to a UK seller. But unfortunately they don't sell to Germany, maybe they also only sell to companies?

May I ask whether there is some one in the UK who can buy and send it to me? Of course I have to pay to him before buying / shipping!

73 from Karsten
DL4DAD

If you're sure they won't send to Germany (possibly limited to the UK by Hioki?) I'd be happy to help.

[Wytnucls]

They do send to Germany, but hurry up, before it's gone.
You just need a credit card, your address, email and they'll come back to you with a quote for postage.

[kado]

Hi and thanks for your response,

i ask them for shipping to Germany, this was the answer:

Sorry we only sell to UK based companies.
 
Best regards
 
Ma.. St..... 

So I would be very happy if amiq is willing to help me.
amiq: could you please contact me via pm or email?

Karsten

[amiq]

I've just put a DT4281 and 3801-50 up for sale in the buy/sale thread...

[kjn4685]

Really cool teardown thanks for sharing.

[CosPhi]

Hi guys

Here is finally my full review about the Hioki DT4281.

I used this meter now for almost five month and was most of the time very happy with my Hioki, special because the measure results are so stable. 


First I'll write a bit about the meters housing/body. Second I'll write a bit about the buttons/functions. Third a bit about the measure function itself.


About the body/housing:

I think the first thing I noticed when I got this meter how thick and wide it is. But it never thought “it is to wide” or  “it's to thick”. I also can keep it in my hand, so no problem with the size. But it's clearly on the larger side from what I like.

About the ruggedness, it's clearly not the toughest meter I know, but it will survive everyday in the field. Meters in this size and wight become all a bit less rugged and the Hioki really has really just a bit of rubber on the sides and a bit on the back, .. really just enough, not more.

Like almost all meter there is no rubber on the back, so if work in the field and put the meter on something it might slip away, just like others.

The stand works very well and the meter is very stable by using it. There are also all Power-On options printed on the backside.

The range switch feels very good. Even by trying to set to position between two ranges, the range switch goes by himself left or right in a proper position. Of course it's possible to set the switch between but you really have to wanna do it and even the (like me, I just tried again) you need three or four times to try. Just one thing here. The range switch stand up from the front.

The sockets for the test leads. I guess they are almost a bit to much resisted because of the safety mechanism (closing the A and mA socket. But I never had any problem with the sockets/test leads (never a test lead felt off by accident or so). I just noticed the test leads make contact when the plug almost full is in the socket and not like other on other meters when they'r half out.

There is an second point I dislike on the plugs. I like to have my leads plugged in with the leads go  over the meter and leave on the left side. If I do this on the Hioki, the leads almost run over the range switch because of the short distance between the sockets and the range switch.

The display is very good. Brightness, contrast like on new Fluke 170s (a bit brighter than Agilent's U1272a). Also to see the digits from left, right, top or bottom side no problem at all. The backlight is white and very bright. There are no bright or dark spots at all. There is also a red backlight for the indication from overvoltage/current and continuity (more about the red backlight later).

I never use any from these clips the backside from multimeters to store the test leads. I think the clips on the DT 4281 are not the best, but because I anyway never use I don't care at all (I just tried now to write it here in this review).


About the buttons and the functions:

The DT428x series meters have no menu like much some other meter in the top range. All setting are done with Power-On functions (printed on the stand ) and it all works perfect (ref. Impedance for dBm, 0-20/4-20mA, beeper, clear all memory).

MIN/MAX
Unlike on other meters the Min/Max function is always working in the background. To reset Min/Max there is a CLEAR button just next to the Min/Max button. I very like this feature and the implementation much. Often I like to see a Min or a Max value for each cycle from a machine or something. So I can set the display to Min or Max at display the value. To reset I just have to push the clear button after each cycle. On the display, there is still always the the Min or Max value . Usually on other meters you have to leave the Min/Max mode, start Min/Max mode again and set the display to Min or Max. On the other side the DT428x does not have AVERAGE.

RELATIVE (delta, zero, null)
Starting relative measurements is just an secondary function on this meter. To start you have to push long on the MIN/MAX button. I don't use this often, so no problem for me. Some other people would like to have this as an primary function, like it is on almost all other meters. More bothers me, it is not possible to set a value as reference catched with AUTOHOLD function.

CLEAR
This button is to reset the MIN/MAX and  PEAK function and to clear single stored values.

READ
Load and show stored values. The function jumps over deleted values.

FILTER
To filter higher out higher frequencys in V AC and in V AC+DC mode

BACKLIGHT
Turn the backlight on for about 30s. It's also possible to disable the backlight auto off with a Power-On function (it save the setting, not an single time function).

RANGE/AUTORANGE
The function is like on every meter. But … by setting the range manual, the range is showed on the main display and disappears after about half a second. So there is no visual info about the actual range. If the voltage is higher than the range (manual/ auto just over max voltage) the display turn red. So even with backlight on there is an visual indication. You can like it or not …

HOLD/AUTOHOLD
Works well, does autorange in this mode too. Sadly no values can be used for relative . But the values can be stored.

MEM
Save values. With the cursor buttons it is possible to choose the memory number / storage place. Very easy to use.

SLOW
Set the display rate to 1 time per second and does average the values. So on a slow PWM signal from for example on a heating element, the showed value is pretty stable and close to the calculated value. On the Hioki the function is way better implemented than the “Smooth” function on my Agilent U1272a.

PEAK VOLT/AMPERE
Does not autorange. Fixed to 18,180,1500V AC/ 6,60,600,1000V DC/ 6,60,600,1000V AC+DC// 1200,12000uA /120,1200mA
Always both Peak Max and Min values showed on the display on the same time.




So, now the most important part. How does the meter his main job, how does it measure?

In short … it does everything very, very well. Very stable, repetitive and rock solid readings, no flickering last digits. The meter just give you the feeling:“You can trust me”.


But also here a bit more about each function.


V AC/ dBm/ dBV/ Current clamp
Does autorange from 60,000mV AC to 1000,0 V AC on the same range position and always show the voltage and the frequency. I don't remember exactly on how low the frequency is correct showed. I just remember it was a bit lower than on the Agilent U1272a. The reading is fast and stable.

In all voltage ranges the display turns red as soon the voltage is larger than the range (in each range if manual, just over 1000V in auto).

The dBm/ dBV in never really used.

The current clamp function is one thing Hioki really fucked up on this meter.
First just in AC, not DC and AC+DC.
Second, even Hioki itself has has clamps and rogowski coils with 1,10,100,1000A to 1,10,100mV ratio, Hioki also has also three (just) AC clamps with other ratios and this meter is just build for this three exotic clamps . It is possible to cheat the ratio so it does match to my clamp, but my clamp has a much higher ranges than these three small Hioki clamps. So soon the display turn red and does show overcurrent, but no value. I really don't understand this. Special because most Hioki's clamps and rogowski coils does not match tho this meter with these ratios and overcurrent settings.
Of course I can use my clamp without this mV to A recalculate function, but it would be much nicer with ...


V DC
Does autorange from 60,000mVDC to 1000,0 VDC. Does it fast and stable. Because it has a higher input impedance on the mV range it often is switching between 600mV and 6V  range in the field with nowhere connected leads. So there is just a dot moving on the display. But so it is with two different impedances. With autorange it is probably the fastest meter I know, in manual range from 0 to 20V it is about the same as a Fluke 170 in manual range.


V AC+DC
Does autorange from 6,0000 V to 1000,0 V. Like on the other voltage functions, 5x display update per second. Does show voltage and frequency at the same time. Does everything well and stable.


Continuity and Diode test
On the continuity check you can easy and always set the threshold value by the cursor buttons on the right side to 20,50,100,500 Ohm. The beep is fast like on a Fluke and the red backlight start to light up (solid, not blinking). So even with with the backlight on there is an clear a different visual signal. After release there is no backlight, if there was no before, or there is the white backlight again, if there was the backlight was on before (on the Agilent is always the backlight off after).


Diode test
Here is also easy to set the treshold just by the cursor buttons from 0.15, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0V and it can measure up to 3.6V. If the voltage is lower on a diode, or a short, the display also turns red.


Ohm
Very fast, very stable. 60.000Ohm-6.000MOhm, 60.00MOhm, 600.0MOhm
The Fluke 170 is a bit faster by shorting the shorting the leads but also misses two ranges (600MOhm, 60Ohm).


Temperature
Just one update per second, but that's mostly ok. The reading are about the same as other Flukes, just my Agilent is about 1 °C lower.


Capacity
On some ranges it is not the fasted meter to measure capacity, but it is clearly not a slow meter. But also here … if there is a value on the display, the value is stable, no settling … repetitive.
Ranges from 1.000nF to 100.0mF.
But to be honest, I almost never used this meter to measure caps, so I tried just a bit lately, so I don't have to write “I never used”.


uA/ mA
Start in DC, change with the SHIFT to AC but not to AC + DC. On AC currents there is also the frequency showed. In the mA range, there is also the 0/4-20mA function. Shows the percentage xx.xx% from 0/4-20mA.


So... I hope I forgot not to much ...



Conclusion

Of course the meter is a bit on the higher price side, but for me it was worth it and I never did it regret. The DT4281 is very easy to use but on the other side it has less functionality than some other meter in this price range.

Some people write on the forum “the Hioki has specs like a 289”. But even they may have similar specs, they are very different kind of meters. The DT428x are much more meters like the 87V.

There are just two points who bother my on the meter a bit. You can't take a value from HOLD to RELATIVE (zero, delta) and the other thing with the clamp ratio. I also wish next time they would make it possible to use a clamp ratio in all voltage ranges (DC,AC+DC).


Finally I have to say the big shiny point is the not just fast (just soso fast for capacity) and also very stable and repetitive reading in all ranges. I wrote now many lines of text but the last sentence is the most important here and really thumbs up 


You can easy use all function without lookup howtodo in the manual.


Oh one thing … after the meter did AutoPowerOff, you cannot restart it by pushing a button, you have to turn the range switch off and on again. If you are in any A range you have to remove the test lead because of the shutter... also not so good. But at least the meter does beep 5 or 10 seconds before it shut down.



greetings

[retiredcaps]

Here is finally my full review about the Hioki DT4281.

Thanks for sharing your opinions and insights on this meter.  I would love a Hioki meter, but with my strict valuation buying critera, it may take a while to find one.

[Handyman32]

I have used the DT4282, and must say that it is built in the same spirit as a bench meter. I consider it as a compact handheld bench meter with the advantage of being able to use AA rechargeable batteries!
It is not as rugged as a Fluke handheld, not weatherproof either.
Despite a few caveats, this Hioki is still a top meter.
Its price can be prohibitive for many of us. It cannot be cheap either, being a high-end meter.

[KGB]

I had some handheld Hioki meter in the past, but I could never really come to terms with them. Something is always fucked up on them.
In this case which hurts my eyes, the nice large display, but the top third of the screen is blank. Of course, there are rarely used icons and gadgets. But did not find place for the bargraph?

[electr_peter]

Thanks for a detailed review. This Hioki meter is pretty good.

The current clamp function is one thing Hioki really fucked up on this meter.
First just in AC, not DC and AC+DC.
Second, even Hioki itself has has clamps and rogowski coils with 1,10,100,1000A to 1,10,100mV ratio, Hioki also has also three (just) AC clamps with other ratios and this meter is just build for this three exotic clamps . It is possible to cheat the ratio so it does match to my clamp, but my clamp has a much higher ranges than these three small Hioki clamps. So soon the display turn red and does show overcurrent, but no value. I really don't understand this. Special because most Hioki's clamps and rogowski coils does not match tho this meter with these ratios and overcurrent settings.
Of course I can use my clamp without this mV to A recalculate function, but it would be much nicer with ...

U1272A series has arbitrary programmable V/A ratio for clamps and other devices (like uCurrent).

Temperature
Just one update per second, but that's mostly ok. The reading are about the same as other Flukes, just my Agilent is about 1 °C lower.

Does it have internal thermometer? Does it have 0.1 C resolution?

[CosPhi]

Thanks for a detailed review. This Hioki meter is pretty good.

The current clamp function is one thing Hioki really fucked up on this meter.
First just in AC, not DC and AC+DC.
Second, even Hioki itself has has clamps and rogowski coils with 1,10,100,1000A to 1,10,100mV ratio, Hioki also has also three (just) AC clamps with other ratios and this meter is just build for this three exotic clamps . It is possible to cheat the ratio so it does match to my clamp, but my clamp has a much higher ranges than these three small Hioki clamps. So soon the display turn red and does show overcurrent, but no value. I really don't understand this. Special because most Hioki's clamps and rogowski coils does not match tho this meter with these ratios and overcurrent settings.
Of course I can use my clamp without this mV to A recalculate function, but it would be much nicer with ...

U1272A series has arbitrary programmable V/A ratio for clamps and other devices (like uCurrent).

Yes, Agilent did this feature very well on the U1272A. In theory Hioki did it very well too. After three times pushing the blue shift button (dBm,dBV,clamp) there is the clamp mode. In this mode the clamps ratios can be set very easy with the two cursor buttons. Just all the ratios are "special Hioki's ratios". The idea and working with the cursor buttons as itself is great. Just the clamp ratios ...

Also it's not possible like on the Agilent to set any ratio.

Temperature
Just one update per second, but that's mostly ok. The reading are about the same as other Flukes, just my Agilent is about 1 °C lower.

Does it have internal thermometer? Does it have 0.1 C resolution?

Yes it has 0.1C resolution (as each other meter I know).

[hgjdwx]

more pictures

Hallo, I just get a dt4282, and then I found a problem. In the 600V ACV range,  input is lower than the 10V , the DT4282 show 0V,  on the others  range is similar to the law,  are your  meter  is so?