I followed this interesting idea of making a 4-wire Kelvin clamp for DE 5000 by modifying the TL-21 typically supplied with the DE 5000. I also bought the cable already made for sale on Amazon and used by the author of the video. But I haven't had good results. As you can also read from other videos on the same topic, this cable is very cheap but it is of low quality, too long and often has constructive defects in the Clip attacks; defects covered by the self-shrinking sheath. I passed the calibration test both "open" and "short" but then the displayed values vary a lot and the "zero" on resistance after calibration was lost immediately even if I did not turn off the DE5000. To give a quantitative value, visualizations of a few tens of random milliohms were normal. It was useless to do the calibration again because nothing changed. What was also evident was that moving the cables varied the error: as if disturbances entered: Yet I assure you that the "Guard" contact was wired as indicated with care and cleanliness. So I decided to do it all again with a better cable from a Hi-Fi shop. Basically a stereo signal cable that has a red and a white wire both individually shielded. I bought similar Kelvin Clips on Amazon like these: www.amazon.com/Alligator-Clips-Copper-Plated-Kelvin/dp/B08CBWJBXZ/ref=sr_1_17?dchild=1&keywords=clip+kelvin&qid=1615716686&sr=8-17 and I made the cable myself. I also adopted a length about 30 cm. The result was good and stable. The error after calibration fluctuates on resistance values of 1-2 Milliohm and above all when moving the cables with the DE 5000 switched on, the indicated value did not change. I hope I have helped someone.
Very important for these meters as there is no input protection. It's detailed in the manual I believe but it does warrant repeating. Discharge your capacitors!
Don't forget to open/short cal the probes too. They are good meters but I find my Sencore LC102 to be a bit more accurate (when you need the accuracy).
Just be sure to do an open and closed calibration after customizing those leads, and anytime you switch between the tweezers and the clips. It makes a pretty big difference when looking for milliohm differences or measuring precision components. It’s really fast and easy, described in the online manual, once you’ve done it a few times it’s just second nature because it only takes the press of a single button and waiting about 30 seconds to different times
Yep, the calibration is important as you say. I do the same before any critical measurement. Same with my HP 4276A, it's easy and quick enough to do that I just do it out of habit too.
Thanks! I think those big kelvin clips are by far the best leads. Too bad DER doesn't supply them. I did the same with my DER5000. Works great even without cal I get 1mOhm measurements.
Yeah I end up using them all the time. Turns out more convenient for using the meter, the kelvin clips are more manoeuvrable than the entire meter.. :)
I did the same mod a year or two ago… The exact same Kelvin clips from eBay and the exact same adapters. It kept giving me an error with that attachment when trying to calibrate… And I know for 100% certain everything was soldered correctly. I checked it all 1000 times with an army of equipment. Even tested the clips and leads on some of my other LCR meters benchtop and a handheld… And everything worked perfectly. But the attachment wouldn’t work in the D 5000, however the SMD tweezers and original gator clip attachment still worked perfectly. No idea what the problem was. I remove the batteries from the De5000 and put it back in the case. Then a few weeks later when I needed it for a repair job in the field…… I plugged it in and everything worked fine. Calibrated the new Calvin leads and everything’s been great since. No idea what the problem was. I couldn’t have done more textbook job… Had to assume it was in the software, considering the device is programmed for short leads, and isn’t used to anywhere near that type of resistance and capacitance in the leads… That the machine has to “zero“ itself. I’ve even seen documentation from that company warning against using longer leads… But I recalibrate it regularly now, and everything works fine. Another observation… There’s no battery reverse or input protection. So if you put the battery in wrong it will blow a few SMD parts on the board. That’s apparently happened to several people on the EEV blog and elsewhere. Too bad they don’t have a battery slot which protects against that. Apparently the battery reverse protection and input protection would screw up the readings… So in my opinion… It works better for me if it’s completely accurate and I’m just extra careful to de-energize everything I’m working on… Drain all the caps, and not put the battery in backwards. I really enjoy your channel. The frequent test gear videos are awesome! There aren’t many electronics channels on RUclips that focus on test equipment. And the ones that do usually only play with $10,000 pieces of gear. Although I love my 8.5 digit meter and multifunction calibrators… I can’t afford that stuff without buying untested units, then repairing and recalibrating myself… So it’s more enjoyable to see every day commonly used to test gear.
Huh, strange with the calibration. I can only guess that some values were being held in memory and somehow it was tripping up until the battery swap wiped the memory clean. Maybe it throws errors if the calibration differs too much between calibration runs? Weird, but at least you got it working in the end. Mine calibrate fine so I guess that makes for two votes in favour of this mod. :)
@@saltima by taking measurements before the mod and after. too late now though. Either way, Dont think ot would have been a huge difference considering the very short leads of the original
@@saltima - if you watch the video carefully 1:20 - you'll note he has purchased 2 sets of test clip connectors. So he can test both against each other.
When I tried to modify the test leads of my MESR meter, for longer ones, I was told not to, that "LCR and ESR meters need for their test leads to be short - for more accuracy". So, who's right?
Generally the shorter the better, however any decent meter will have the ability to null (zero) the test leads before each measurement. Specifically... For resistance, the length doesn't matter for resistance if it's a proper 4-wire connection. For low ohms where there is large currents, you want to keep the "power lead" resistance reasonably low but the voltage measurement leads can be thin. Really, these coax cables and cheap Kelvin clips are too small for Low Ohms measurements anyway. For capacitance the length DOES matter (since parallel wires will add capacitance), however these coax leads are shielded so that *_may_* help reduce the effect. For inductance, the length matters especially the leads are coiled, and I am unsure what the effect of any shield will be.
@@johncoops6897 I did the same mod with the exact same leads, however I didn’t keep the full length I shortened them a little bit. Probably shorten them a little less than half of their length. Which helped a lot and help the meter to zero and re-calibrate itself open and closed… More accurately. It’s pretty important to re-calibrate the meter “short and open“ each time you switch leads between the tweezers and the Kelvin clips. If I’m in the field, away from my bench gear… Then I recalibrate it every few minutes if I’m doing critical measurements. It compares really well to my sencore and hp lcr meters, It’s usually just as accurate… But not quite as consistently. There is a difference in precision and consistency. However… If you need something more precise than this regarding resistance and capacitance… Then you’ve already got a lab fill up equipment anyway.
hi can you please posted the brand of your wire cutters that black one you are using on this video I like to get me a pair of those as well. thank you...
They are Engineer brand, model NZ-05, available many places here in Japan, but I'm not sure about availability outside of Japan... www.engineertools-jp.com/
In the video, you cut off the foil shield stub from the probe cables and do not connect it to anything. I take it that you were confident in doing that, because the bare ground wire is likely in contact with the shield, at some point along the cable, thereby making a path for any noise to go to the meter's ground. Many brands of this type of cable also include a nylon string, or core, for physical support, inside the shield, along with the three wires. I think this string, or core, might limit the number of places where the ground and shield make contact. And, the type of connection between the bare ground wire and the shield would only be by physical contact, anyway. That's not really a good connection. Further, I am confident that the manufacturer did not connect the ground and shield at the probe end of the cable. So, I think there is value in wrapping the shield stub into the ground wire and soldering the two to the ground pad on the PCB. I would like your thoughts, in this regard, before I finish soldering up my kit. As an aside for other types of applications with shielded cable, we must always make sure that the way we use, or connect, the cable wires and shield does not allow the shield to become a hidden path to tie the meter to the DUT's, or Earth's, ground. I imagine that the best way to do that is to always use cable that has an insulated ground wire and to only connect the shield to ground at the meter end of the cable and never at the DUT end. Care would have to be observed to prevent the shield from touching the connector case, at the DUT end, because the DUT case might be grounded. This is not my area of expertise, so I hope others will comment. HTH and keeps us safe. I am sorry to be so wordy, I have not had any sleep.
The ground wire is in direct contact with the shield for the entire length of the cable. The way I terminated the ground wire is fine and industry standard for this type of wire. Usually the foil shield is aluminium foil so you won't be able to solder to it anyway.
I purchased my tester and parts from Akizuki Denshi here in Akihabara in Tokyo: (The kelvin leads I used were purchased from ebay) akizukidenshi.com/catalog/goods/search.aspx?search=x&keyword=de-5000
Ahh.. Made the same mod to mine “dairy” meter. Stole the idea from Defpom. This company supposedly makes decent multimeters as well. Priced similar to Brymen. That Hakko desoldering gun is sweet, I thought.. so I looked up its price. s%*#t!
I followed this interesting idea of making a 4-wire Kelvin clamp for DE 5000 by modifying the TL-21 typically supplied with the DE 5000.
I also bought the cable already made for sale on Amazon and used by the author of the video.
But I haven't had good results. As you can also read from other videos on the same topic, this cable is very cheap but it is of low quality, too long and often has constructive defects in the Clip attacks; defects covered by the self-shrinking sheath.
I passed the calibration test both "open" and "short" but then the displayed values vary a lot and the "zero" on resistance after calibration was lost immediately even if I did not turn off the DE5000. To give a quantitative value, visualizations of a few tens of random milliohms were normal. It was useless to do the calibration again because nothing changed.
What was also evident was that moving the cables varied the error: as if disturbances entered: Yet I assure you that the "Guard" contact was wired as indicated with care and cleanliness.
So I decided to do it all again with a better cable from a Hi-Fi shop. Basically a stereo signal cable that has a red and a white wire both individually shielded.
I bought similar Kelvin Clips on Amazon like these:
www.amazon.com/Alligator-Clips-Copper-Plated-Kelvin/dp/B08CBWJBXZ/ref=sr_1_17?dchild=1&keywords=clip+kelvin&qid=1615716686&sr=8-17
and I made the cable myself.
I also adopted a length about 30 cm.
The result was good and stable. The error after calibration fluctuates on resistance values of 1-2 Milliohm and above all when moving the cables with the DE 5000 switched on, the indicated value did not change.
I hope I have helped someone.
I have this meter. And it's a really good LCR. Worth checking caps are discharged before connecting.
Fancy seeing you here Simon.
Very important for these meters as there is no input protection.
It's detailed in the manual I believe but it does warrant repeating.
Discharge your capacitors!
I successfully modified my TL-21 adapter as described in the video (although I ordered clips and wires elsewhere). Many thanks for sharing!
Don't forget to open/short cal the probes too. They are good meters but I find my Sencore LC102 to be a bit more accurate (when you need the accuracy).
And polarity matters when it comes to electrolyte capacitors.
So it's always a good idea to connect the positive to the red one
Just be sure to do an open and closed calibration after customizing those leads, and anytime you switch between the tweezers and the clips. It makes a pretty big difference when looking for milliohm differences or measuring precision components. It’s really fast and easy, described in the online manual, once you’ve done it a few times it’s just second nature because it only takes the press of a single button and waiting about 30 seconds to different times
Yep, the calibration is important as you say. I do the same before any critical measurement. Same with my HP 4276A, it's easy and quick enough to do that I just do it out of habit too.
@@NearFarMedia but you did not do that be for you tested tho
Thanks! I think those big kelvin clips are by far the best leads. Too bad DER doesn't supply them. I did the same with my DER5000. Works great even without cal I get 1mOhm measurements.
Yeah I end up using them all the time. Turns out more convenient for using the meter, the kelvin clips are more manoeuvrable than the entire meter.. :)
I did exactly the same modification to my DER5000 (and video) a couple of years ago.
Oh nice, I was beaten to it. :D
I did the same mod a year or two ago… The exact same Kelvin clips from eBay and the exact same adapters. It kept giving me an error with that attachment when trying to calibrate…
And I know for 100% certain everything was soldered correctly. I checked it all 1000 times with an army of equipment. Even tested the clips and leads on some of my other LCR meters benchtop and a handheld… And everything worked perfectly. But the attachment wouldn’t work in the D 5000, however the SMD tweezers and original gator clip attachment still worked perfectly.
No idea what the problem was. I remove the batteries from the De5000 and put it back in the case. Then a few weeks later when I needed it for a repair job in the field…… I plugged it in and everything worked fine.
Calibrated the new Calvin leads and everything’s been great since. No idea what the problem was.
I couldn’t have done more textbook job… Had to assume it was in the software, considering the device is programmed for short leads, and isn’t used to anywhere near that type of resistance and capacitance in the leads… That the machine has to “zero“ itself. I’ve even seen documentation from that company warning against using longer leads… But I recalibrate it regularly now, and everything works fine.
Another observation… There’s no battery reverse or input protection. So if you put the battery in wrong it will blow a few SMD parts on the board. That’s apparently happened to several people on the EEV blog and elsewhere. Too bad they don’t have a battery slot which protects against that.
Apparently the battery reverse protection and input protection would screw up the readings… So in my opinion… It works better for me if it’s completely accurate and I’m just extra careful to de-energize everything I’m working on… Drain all the caps, and not put the battery in backwards.
I really enjoy your channel. The frequent test gear videos are awesome! There aren’t many electronics channels on RUclips that focus on test equipment. And the ones that do usually only play with $10,000 pieces of gear. Although I love my 8.5 digit meter and multifunction calibrators… I can’t afford that stuff without buying untested units, then repairing and recalibrating myself… So it’s more enjoyable to see every day commonly used to test gear.
Huh, strange with the calibration. I can only guess that some values were being held in memory and somehow it was tripping up until the battery swap wiped the memory clean.
Maybe it throws errors if the calibration differs too much between calibration runs? Weird, but at least you got it working in the end.
Mine calibrate fine so I guess that makes for two votes in favour of this mod. :)
It's been a long time, but you have to adjust the frequency of the capacitor. Generally >10uF - 100 Hz;
As a true Kelvin meter, I guess this is better than the UT-612? Thanks for the video and insight into this device.
Unfortunately, I have no experience with the UT-612 so I can't say, sorry.
This meter use in pcb components ya out side components only test out side
Would you mind doing comparison measurements between the stock tl-21 and the 4-wire modded one?
@@saltima by taking measurements before the mod and after. too late now though. Either way, Dont think ot would have been a huge difference considering the very short leads of the original
@@saltima - if you watch the video carefully 1:20 - you'll note he has purchased 2 sets of test clip connectors. So he can test both against each other.
When I tried to modify the test leads of my MESR meter, for longer ones, I was told not to, that "LCR and ESR meters need for their test leads to be short - for more accuracy". So, who's right?
Generally the shorter the better, however any decent meter will have the ability to null (zero) the test leads before each measurement. Specifically...
For resistance, the length doesn't matter for resistance if it's a proper 4-wire connection. For low ohms where there is large currents, you want to keep the "power lead" resistance reasonably low but the voltage measurement leads can be thin. Really, these coax cables and cheap Kelvin clips are too small for Low Ohms measurements anyway.
For capacitance the length DOES matter (since parallel wires will add capacitance), however these coax leads are shielded so that *_may_* help reduce the effect.
For inductance, the length matters especially the leads are coiled, and I am unsure what the effect of any shield will be.
@@johncoops6897 I did the same mod with the exact same leads, however I didn’t keep the full length I shortened them a little bit. Probably shorten them a little less than half of their length. Which helped a lot and help the meter to zero and re-calibrate itself open and closed… More accurately. It’s pretty important to re-calibrate the meter “short and open“ each time you switch leads between the tweezers and the Kelvin clips. If I’m in the field, away from my bench gear… Then I recalibrate it every few minutes if I’m doing critical measurements.
It compares really well to my sencore and hp lcr meters, It’s usually just as accurate… But not quite as consistently. There is a difference in precision and consistency.
However… If you need something more precise than this regarding resistance and capacitance… Then you’ve already got a lab fill up equipment anyway.
hi can you please posted the brand of your wire cutters that black one you are using on this video I like to get me a pair of those as well. thank you...
They are Engineer brand, model NZ-05, available many places here in Japan, but I'm not sure about availability outside of Japan...
www.engineertools-jp.com/
@NFM do you like peeling your skin after a sunburn too? ;)
How could you tell? :D
In the video, you cut off the foil shield stub from the probe cables and do not connect it to anything. I take it that you were confident in doing that, because the bare ground wire is likely in contact with the shield, at some point along the cable, thereby making a path for any noise to go to the meter's ground. Many brands of this type of cable also include a nylon string, or core, for physical support, inside the shield, along with the three wires. I think this string, or core, might limit the number of places where the ground and shield make contact. And, the type of connection between the bare ground wire and the shield would only be by physical contact, anyway. That's not really a good connection. Further, I am confident that the manufacturer did not connect the ground and shield at the probe end of the cable. So, I think there is value in wrapping the shield stub into the ground wire and soldering the two to the ground pad on the PCB. I would like your thoughts, in this regard, before I finish soldering up my kit. As an aside for other types of applications with shielded cable, we must always make sure that the way we use, or connect, the cable wires and shield does not allow the shield to become a hidden path to tie the meter to the DUT's, or Earth's, ground. I imagine that the best way to do that is to always use cable that has an insulated ground wire and to only connect the shield to ground at the meter end of the cable and never at the DUT end. Care would have to be observed to prevent the shield from touching the connector case, at the DUT end, because the DUT case might be grounded. This is not my area of expertise, so I hope others will comment. HTH and keeps us safe. I am sorry to be so wordy, I have not had any sleep.
The ground wire is in direct contact with the shield for the entire length of the cable. The way I terminated the ground wire is fine and industry standard for this type of wire.
Usually the foil shield is aluminium foil so you won't be able to solder to it anyway.
Where did you find the LCR and all accessory's for under a hundred bucks? I pay 220 euro's for the LCR alone here..
I purchased my tester and parts from Akizuki Denshi here in Akihabara in Tokyo:
(The kelvin leads I used were purchased from ebay)
akizukidenshi.com/catalog/goods/search.aspx?search=x&keyword=de-5000
@@NearFarMedia It seems this company only ships withing Japan. I live in the Netherlands :) Prices are way higher here.
Ahh.. Made the same mod to mine “dairy” meter. Stole the idea from Defpom. This company supposedly makes decent multimeters as well. Priced similar to Brymen. That Hakko desoldering gun is sweet, I thought.. so I looked up its price. s%*#t!
Yeah, The Hakko ain't cheap... I have it hooked up to a Hakko FM-206 station and it works well.
Not a cheap unit but I use it every day and love it.
It is hardly low end for handheld meters.
didnt do before after test huh