#1688

Episode 1688
on loan from Keysight. $25,000 LCR meter
Be a Patron: / imsaiguy

[@mikesradiorepair]

If you want to demonstrate one of the practical uses of the DC bias function you should show testing varactor diodes. This is one of the reasons I bought a modern high end LCR meter, to quickly batch sort varactor diodes. Sweep the DC bias over the listed range of the varactor diode and measure it's capacitance at each voltage step.

[@IMSAIGuy]

I've already made a video, in a few days, also on voltage dependent caps

[@JoshuaNorton]

Ohhh, I wish you could keep this and try to make DIY capacitance standards. There is a paper on the Internet somewhere describing how NIST made their standards back in the 60s: They took quartz disks, lapped them parallel, coated them with lacquer containing silver particles, burned out the the lacquer to leave an evenly distributed silver coat . Then they ran a knife across the disk edge to scrape off the excess silver and separate the two opposing sides as the capacitor plates. Finally, the capacitor was suspended on the connecting electrodes to and put inside a metal container with an inert gas. Apparently the scraping part was critical in keeping the longterm drift within ppm range. Sounds surpsingly doable, right? Would have been an amazing project to try and then actually track the drift over time.

[@Manf-ft6zk]

Nice instrument. When defining secondary standards take care of the temperature dependency at least when touching the capacitors by hand. With the high resolution that you have it will be easy to find the most constant ones.

[@lmamakos]

With that huge measurement range, it would be interesting to characterize a variety of "gimmick" capacitors from just twisting together insulated wire. Figure out a rule-of-thumb for some available wire gauge and insulation combinations for when you need that 1.25 pF capacitor in the future.

[@IMSAIGuy]

good idea

[@jms019]

What a lovely toy !

[@IanScottJohnston]

Nice LCR meter.......I've always been on the lookout for an affordable Bench LCR meter. Sadly, the E4980A is about 6k UK.

[@Janktzoni]

Keysight announces € 23.522 including delivery, well... If it really is 6k£ then that is a bargain!

[@IanScottJohnston]

@@Janktzoni Ahhhh, RS Components are saying 6k for the E4980AL .......the lower spec unit.

[@Edisson.]

Hello, both machines are great and it's nice to see how the development is moving forward 🤔 yeah, a friend like that would probably be good for each of us 😂 For a long time, I have been guarding one capacitor + resistor + coil like an eye in my head and sometimes I check my LCR meter with them, I don't even know if they are still within tolerance. I'm really looking forward to the setup video Nice day 🙂 Tom

[@markgunnison]

Really cool.

[@tizianob8590]

What an instrument! Would be interesting to measure the tempco of these capacitors (warm them up and see how much they drift).

[@gorak9000]

It comes with "what a pricetag" too - I don't even know why people make YT videos about stuff like this - the hobbyist isn't going to be able to afford one of these, and if you can afford one of these, you're probably not watching YT videos to see how to use it...

[@zyeborm]

​@@gorak9000there's a reason why Microsoft and Adobe etc make their products almost free to schools. As well as the "educational" versions of scopes and things being cheaper. People don't start off as experts they start off with an interest then they become experts and start making purchasing decisions. What will they choose to buy? The thing they are comfortable with. Even when it's more expensive than an equivalent product from a competitor.

[@PapasDino]

Nice to have friends in high places! ;-)

[@alanumanacastillo5769]

Hi, thanks for the video! Do you think this LCR meter can be used to measure the capacitance and inductance on PCB traces? I have, let's say, theorical data for capacitance and inductance in the traces of a PCB from simulations that I would like to check in the manufactured PCB, mainly in pF and nH. I made some measurements, and the values were not close to the theorical values, so I want a second opinion. Thanks in advance! :)

[@tubosolinas]

Don't turn it ooon!Take it apaaaart 😂

[@idreesibhai8056]

Please reply anybody ..We have that LCR meter but not have that fixture probe( where we put the the capacitor or inductor). So can we measure the inductance or capacitance without it? Kindly answer me 🙏

[@polaraligned1]

Definitely measure those caps that vary with voltage!!

[@IMSAIGuy]

tomorrows video

[@TeslaTales59]

I still like the old one better. Does not have to "boot up".

[@xenoxaos1]

On loan... Hey... Yeah... I sent that back last week... Didn't you get it?

[@jspencerg]

More significant digits mean more precision, not more accuracy.

[@Chris-hy6jy]

Significant digits?

[@jspencerg]

@@Chris-hy6jy Also known as significant figures en.m.wikipedia.org/wiki/Significant_figures

[@zyeborm]

Except in the case of gear like this where it'll be specified probably down to those last digits to be accurate

[@bradbrown620]

Wow! Its good to have friends in high places that can send you a toy like that. Those bad boys are not cheap.

[@joeteejoetee]

How do you measure the Q of an inductor?

[@IMSAIGuy]

www.electronics-notes.com/articles/basic_concepts/q-quality-factor/inductor-q-factor.php

[@joeteejoetee]

Thank you very much @@IMSAIGuy !

[@daveodessa]

If you bought the E4980A from Keysight would they give you a family and friends discount. Thanks for the video.

[@IMSAIGuy]

no, and the discount these days is really a joke, only some products, some times and only 10%. Back in the day HP gave really good discounts to everything

[@R2AUK]

But what is D? Deviation?

[@IMSAIGuy]

dissipation factor: en.wikipedia.org/wiki/Dissipation_factor I explain: kzbin.info/www/bejne/aWWqZaOwjNdsoaMsi=eahKM2JhEMTOGvcU

[@fredmitchel1236]

And the lower D ...the better capacitor... It is nice Keysight your old employer was so generous... Two days ago we needed to measure insulation resistance for our customers parts.... Spec.: Insulation resistance needs to be greater than 0.5 Tohm at 500 VDC... Our customer specified some Keysight ohmmeter... We got a quote...$21.5 K... Amazing the cost... For now we will use the old megger...it can read up to 1 G ohm ...so we are looking and screening for gross leakage..but not testing per spec.... There are discussions on who will pay for the Keysight... I was going to see if we had a sensitive ammeter... 500 V / 500 G ohm = 1 nA max - leakage current We don't have an ammeter that can measure a nano amp... I think my old Keithley...the lowest scale is 200 uA.. Look how easy I go off subject. ... LOL

[@Gengh13]

​@@fredmitchel1236you can use a DMM in voltage mode as a pretty sensitive leakage current measurement device, 1na over 10MOhm or whatever resistance it has on a low range is 10mV.

[@fredmitchel1236]

@Gengh13 Thanks Gengh 13... Ya the plot thickens.... Reading the spec more....it calls out for that Keysight - which is obsolete as of 2016...and now can be bought for $1500... When reading their spec more..they were using the Keysight 4 terminal ohmmeter feature to measure the heater element resistance which were around 8 to 9 ohms, another element 9 to 10 ohms and then last element at 10 to 13 ohms... And so then we could use our garden variety Fluke 116 DVM to look for trouble easily Reading closer - insulation R to chassis ground - to be greater than 500 G ohm at 500 VDC... Spec said use a megger ... We bought one that will read up to 1 Tera ohm..but found out it only can measure that high when test voltage was 5 kV... When set to 500 VDC- its highest resistance that can be measured was 500 Mohms... I saw some internet techniques .. One group in from UT in Austin..were playing with their voltmeter and were trying to reliably cal a sensitive Keithley...and wanted to source like 5 pA...to calibrate another Keithley... So yes I like to see how one could create a tester...to source 500 VDC...and measure the voltage across a known high resistor.. Then calculate the resistance of the insulation you have 500 VDC as source supply...to stress the insulation.....then say I found or bought a 20 Meg ohm resistor resistor...perhaps that might be the highest in my goodie boxes... 20 Meg ohm...per volt?...like the garden variety Fluke input Z probably has... And for argument sake...say the heat wire insulation resistance was just in spec and was 500,000,000,000 + 1 Meg ohm..to make believe a heater insulation is just in spec... So 500 VDC forced through 20 Meg + 500 Gohm + 1 Meg ohm , Rt be 500,021,000,000 total ohms And the current would be 9.995002 × 10-9.. And the voltage across the 20 Meg resistor would be 9.99 mV... And the I could measure with garden variety Fluke DVM...for pass fail until the Keysight fancy ohm meter arrives and would tell me with 6.5 digits what a more accurate reading is...My Fluke might read 10.45 ohms...the Keysight 10.454725 ohms...and the spec. is 10 to 13 ohms...and this heater element would be wonderful So we go to the insulation resistance set up....I place the Fluke 77 or Fluke 116 DVM across the 20 Meg ohm resistor...and measure DC voltage.. Won't I bog my 20 Meg ohm resistor and get half the voltage?... So I would say then if the voltage is 5 mV or lower then the insulation resistance is just over 500 giga ohms? Thanks for reading a story... I am just going to ask the make and model of their megger....then we will get that too. I already found a two element part that had one heater element insulation resistance at 6 megs ohms using the Fluke 116...boom and that part was rejected.. Happy Thanksgiving 2023...almost.. I think or probably IMASI already used something and measured some high resistance.. That is good he is building some std. Capacitor standards... Take care

[@fredmitchel1236]

Thanks IMSAI for link to D. I remember the Q of a capacitor being 1/D... Then most good caps have high Q

[@robertperlstein3527]

Nice toy-- too bad it's 24,000 buckaroos-- kind of out of reach for most private individuals..