Hioki DT4281 Multimeter : Teardown and first impression - Page 1
Forum section: electronics / testgear

author: CosPhi
author_rank: Regular Contributor
timestamp: August 30, 2014, 09:42:57 pm
content: Hi guysREVIEWhttps://www.eevblog.com/forum/testgear/hioki-dt4281-multimeter-teardown-and-first-impression/msg601911/#msg601911I 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 ACIf somebody has questions, just ask.

author: CosPhi
author_rank: Regular Contributor
timestamp: August 30, 2014, 09:48:15 pm
content: more pictures

author: CosPhi
author_rank: Regular Contributor
timestamp: August 30, 2014, 09:49:40 pm
content: and more

author: retiredcaps
author_rank: Super Contributor
timestamp: August 30, 2014, 10:36:52 pm
content: 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?

author: radhaz
author_rank: Regular Contributor
timestamp: August 31, 2014, 12:41:02 am
content: Thanks for the teardown. You have saved me the trouble of taking mine apart.It certainly is a quality DMM.

author: Lightages
author_rank: Unknown
timestamp: August 31, 2014, 01:40:23 am
content: Now THAT is a well made meter. Too bad they aren't more common.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 31, 2014, 02:40:23 am
content: Quote from: Lightages on August 31, 2014, 01:40:23 amAt $400 USD, I would expect quality to meet or exceed the top equipment makers.

author: Vgkid
author_rank: Super Contributor
timestamp: August 31, 2014, 04:27:10 am
content: That is a really nice looking meter.

author: Wytnucls
author_rank: Super Contributor
timestamp: August 31, 2014, 04:55:37 am
content: 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.

author: jasonlang
author_rank: Newbie
timestamp: September 04, 2014, 07:13:54 am
content: Thanks for sharing the teardown pictures. I am focused on this Multimeter.Where is the precision resistor? Under the LCD display?

author: CosPhi
author_rank: Regular Contributor
timestamp: September 14, 2014, 01:44:58 pm
content: Hi guysI'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 includedhttp://www.ittsb.eu/DT4282%20review.htmlI 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 20AmpsThis 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

author: CosPhi
author_rank: Regular Contributor
timestamp: September 14, 2014, 02:06:31 pm
content: For people from the UKhttp://www.testtoolsshop.com/hioki-dt4281_professional-multimeter-providing-efficient-high_precision-measurement-343A new DT4281 for just £129.00.

author: kado
author_rank: Regular Contributor
timestamp: September 15, 2014, 05:02:43 pm
content: 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 KarstenDL4DAD

author: amiq
author_rank: Regular Contributor
timestamp: September 15, 2014, 06:03:33 pm
content: Quote from: kado on September 15, 2014, 05:02:43 pmIf you're sure they won't send to Germany (possibly limited to the UK by Hioki?) I'd be happy to help.

author: Wytnucls
author_rank: Super Contributor
timestamp: September 15, 2014, 06:08:50 pm
content: 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.

author: kado
author_rank: Regular Contributor
timestamp: September 16, 2014, 04:15:48 am
content: 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 regardsMa.. 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

author: amiq
author_rank: Regular Contributor
timestamp: October 02, 2014, 02:58:54 pm
content: I've just put a DT4281 and 3801-50 up for sale in the buy/sale thread...

author: kjn4685
author_rank: Regular Contributor
timestamp: October 02, 2014, 06:24:38 pm
content: Really cool teardown thanks for sharing.

author: CosPhi
author_rank: Regular Contributor
timestamp: February 04, 2015, 08:40:30 pm
content: Hi guysHere 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/MAXUnlike 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.CLEARThis button is to reset the MIN/MAX and PEAK function and to clear single stored values.READLoad and show stored values. The function jumps over deleted values.FILTERTo filter higher out higher frequencys in V AC and in V AC+DC modeBACKLIGHTTurn 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/AUTORANGEThe 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/AUTOHOLDWorks well, does autorange in this mode too. Sadly no values can be used for relative. But the values can be stored.MEMSave values. With the cursor buttons it is possible to choose the memory number / storage place. Very easy to use.SLOWSet 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/AMPEREDoes not autorange. Fixed to 18,180,1500V AC/ 6,60,600,1000V DC/ 6,60,600,1000V AC+DC// 1200,12000uA /120,1200mAAlways 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 clampDoes 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 DCDoes 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+DCDoes 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 testOn 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 testHere 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.OhmVery fast, very stable. 60.000Ohm-6.000MOhm, 60.00MOhm, 600.0MOhmThe Fluke 170 is a bit faster by shorting the shorting the leads but also misses two ranges (600MOhm, 60Ohm).TemperatureJust 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.CapacityOn 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/ mAStart 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 ...ConclusionOf 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 upYou 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

author: retiredcaps
author_rank: Super Contributor
timestamp: February 04, 2015, 11:09:37 pm
content: Quote from: CosPhi on February 04, 2015, 08:40:30 pmThanks 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.

author: Handyman32
author_rank: Newbie
timestamp: February 05, 2015, 05:40:01 am
content: 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.

author: KGB
author_rank: Contributor
timestamp: February 05, 2015, 05:49:09 pm
content: 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?

author: electr_peter
author_rank: Unknown
timestamp: February 05, 2015, 08:26:29 pm
content: Thanks for a detailed review. This Hioki meter is pretty good.Quote from: CosPhi on February 04, 2015, 08:40:30 pmU1272A series has arbitrary programmable V/A ratio for clamps and other devices (like uCurrent).QuoteDoes it have internal thermometer? Does it have 0.1 C resolution?

author: CosPhi
author_rank: Regular Contributor
timestamp: February 08, 2015, 08:00:57 pm
content: Quote from: electr_peter on February 05, 2015, 08:26:29 pmYes, 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.QuoteYes it has 0.1C resolution (as each other meter I know).

author: hgjdwx
author_rank: Regular Contributor
timestamp: October 30, 2015, 05:26:36 am
content: Quote from: CosPhi on August 30, 2014, 09:48:15 pmHallo, 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?

author: retiredcaps
author_rank: Super Contributor
timestamp: October 30, 2015, 06:04:27 am
content: Quote from: hgjdwx on October 30, 2015, 05:26:36 amCan you rephrase or give some clear examples of what you are writing above? I can't understand what you are trying communicate?

author: hgjdwx
author_rank: Regular Contributor
timestamp: October 30, 2015, 06:31:28 am
content: Quote from: retiredcaps on October 30, 2015, 06:04:27 amsorry?I mean, in the AC600V manual range, input is under AC10V ,DT4282 shows "0"

author: retiredcaps
author_rank: Super Contributor
timestamp: October 30, 2015, 06:54:37 am
content: Quote from: hgjdwx on October 30, 2015, 06:31:28 amIf I understand this, you are trying to measure something that is 8VAC (example). When you put the meter into 600V manual range mode you expect to see 8V, but you see 0V.If yes and I'm interpreting the manual correctly, then according to the DT4282 manual, page 80, it states for AC readingsAccuracy specification range - 5% or more of each rangeThat is, the reading has to be at least 600V x 5% = 30V. So if you try reading 8V in the 600V range, it doesn't meet the 30V minimum voltage required to get a proper reading. Try reading a 31VAC source in the 600V range. It should show 31V.

author: hgjdwx
author_rank: Regular Contributor
timestamp: October 30, 2015, 07:26:51 am
content: Quote from: retiredcaps on October 30, 2015, 06:54:37 amthank you! you are right! but my 187 and U1272A Without this phenomenon . I just want to know, this DT4282, it's right or no

author: hgjdwx
author_rank: Regular Contributor
timestamp: October 30, 2015, 04:25:10 pm
content: hello every body, I'm from China, my English is poor.who having DT4281/DT4282, please check it, and whether there is the same situation?thanks very much!

author: electr_peter
author_rank: Unknown
timestamp: October 30, 2015, 07:23:19 pm
content: I suspect Hioki implemented software feature to show 0V when AC input is below certain threshold. Agilent, on the other hand, chose not to use any software threshold and show things as they are. I prefer the Agilent way - show things as they are (even with error) and let me think what is happing rather than put false label 0 AC V which can be very dangerous and misleading.Why did Hioki (and some other manufacturers) set DMMs to show 0V even when it is not exactly true? Well, for several reasons:TRMS AC range will never show 0 AC even with shorted probes - it is by design of TRMS, not much one can do there. Therefore, this is difficult to comprehend to a typical user and difficult to communicate to public. So they simply "hide" it.Few AC V reading with shorted probes on TRMS meter is viewed as an error/defect by uninformed users, while it is not a error at all.600 AC V range is"supposed"to be used on mains voltages (100-250 AC) and not on 8 AC V voltages. One should use 60V range for such voltage - better resolution and accuracy is achieved this way.600 AC range is"supposed"to show only if there is dangerous voltage or not (use case in most electrical situations) and NOT to show all the details at low level.Clearly, forum userhgjdwxis more clever than "typical user" and asks the right questions. He/she is thinking with his/her own head and does not take assumptions that 0V on DMM LCD is 0V in reality. Good for you

author: hgjdwx
author_rank: Regular Contributor
timestamp: October 31, 2015, 12:37:28 pm
content: Quote from: electr_peter on October 30, 2015, 07:23:19 pm

author: CosPhi
author_rank: Regular Contributor
timestamp: October 31, 2015, 07:15:20 pm
content: I use AC almost just for measure on mains voltage or on mV for with the current clamp. I have my Hioki not at home today, so I can't test it now. But I'll do it tomorrow or on Monday to confirm.But I guess they do some filtering to have this very stable display.On the picture I attached to my review (2nd page of this thread) you also can see the other meters show a small AC value, except the Hioki.You will hear from me again soon ...

author: CosPhi
author_rank: Regular Contributor
timestamp: November 12, 2015, 06:17:06 pm
content: I tryed it with my DT4281 this week too.Here some data ...Real voltage HiokiHioki DT4281 in manual, 600V AC, mode5.1V AC 0.00V AC5.6V AC 1.04V AC6.6V AC 3.18V AC7.6V AC 5.10V AC9.6V AC 9.00V AC10.1V AC 9.98V ACHioki DT4281 in manual, 1000V AC, mode10.2V AC 0.2V AC15.1V AC 10.0V AC20.0V AC 19.8V ACFor me that's no problem. On the same time I tryed it with a Fluke 179 too ... it did a perfect job spot on from 0V all the way up..It seems on the 600V range you have to get over 5V to see "something" and from about 10V the showed value is correct.In the 1000V range you have to get over 10V to get a value on the display and from about 20V the showed value is correct.

author: hgjdwx
author_rank: Regular Contributor
timestamp: November 15, 2015, 02:30:59 pm
content: Quote from: CosPhi on November 12, 2015, 06:17:06 pmThank you for helping me solve the problem?

author: electr_peter
author_rank: Unknown
timestamp: November 15, 2015, 10:52:15 pm
content: CosPhi, thanks for the measurement data. Based on this information, one can assume and estimate that HIOKI DT4281 uses such algorithm to convert input AC RMS voltage to displayed voltage:0 V, if input voltage is less than 5 Vinput*2 - 10, if input voltage is in interval [5, 10)input, if input voltage is equal or greater than 10 VEstimates are based on readings from 600 V range. 1000V range looks the same, only that all values are double.This evidence supports my post above that HIOKI DT4281 uses software threshold method on low voltage levels to hide AC RMS converter noise.

author: timofonic
author_rank: Frequent Contributor
timestamp: November 16, 2015, 01:34:50 am
content: Damn. This is disappointing...Does it happen to other DMMs?

author: timofonic
author_rank: Frequent Contributor
timestamp: November 23, 2015, 06:55:26 pm
content: No more info?

author: Hydrawerk
author_rank: Super Contributor
timestamp: July 27, 2016, 11:18:32 pm
content: I wonder how Hioki DT4281 can be 1 meter drop proof with such a little rubber holster.https://www.eevblog.com/forum/testgear/hioki-dt4281-multimeter-teardown-and-first-impression/?action=dlattach;attach=134309;imageFluke 87V is also 1 meter drop proof but it has a bigreplaceablerubber holster...https://www.eevblog.com/forum/testgear/fluke-87v-87-5-87-v-gsm-interference-fluke-says-firmware-flash-fixes-it/?action=dlattach;attach=67015;image

author: exo
author_rank: Newbie
timestamp: March 06, 2017, 06:00:18 am
content: Hioki DT4281 + Fluke TL175 TwistGuard Test Leads =compatible ?

author: electr_peter
author_rank: Unknown
timestamp: March 06, 2017, 07:31:39 pm
content: Quote from: exo on March 06, 2017, 06:00:18 amYes, DMM and test leads should be compatible. Hioki DT4281 has standard 4 mm banana sockets, Fluke TL175 has standard 4mm banana plugs -> compatible.Only few DMMs and test lead combinations (as reported on this forum) had problems of very loose (or very stiff) connections between standard 4mm sockets and sockets (because of loose tolerances). Hioki and Fluke are high quality brands, it should fit perfectly.