Re: [volt-nuts] Bohnenberger electrometer
Hi Dave: Here's a free on line book "Magnetism and Electricity", 1877 https://books.google.com/books?id=y45PYAAJ=PA169#v=onepage=false Chapter 6 Electroscopes and Electrometers starts on book page 74 (pdf pg 81) but . . Chapter 11 Voltaic, Dynamical or Current Electricity is where paragraph 214 Bohnenberger's Electroscope appears on book pg 169 (pdf 176). This is the chapter for the Voltaic Pile so that's probably why since it's a way to testing polarity. -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Original Message Bohnenberger electrometer ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Anyone got a photo of a 3458A with "new volt" printed on it?
Hi Dave: I remember this. We already had an HP 3458 that was calibrated to the Old Volt and I ordered a new one that came with a "new volt" sticker. Tom, in the cal lab, connected them both to a voltage standard (maybe the Fluke 332) and the difference in their readings was very close to the deference in the definitions. Note the voltage source does not need to be accurate for this comparison, just stable. http://www.prc68.com/I/HP3458DVM.shtml http://www.prc68.com/I/Fluke332B.html PS Let me know if you find a photo of the sticker. -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Original Message IIRC, there are reports of 3458A's being sent to Agilent, and having a sticker to say the "new" standard volt was used - I assume the last time the volt was redefined. I was chatting to someone from my radio club in the pub last night, and somehow we got onto the definition of a volt. I'd like to try to research this, and perhaps give a talk at our radio club on it. I'd like to get a picture of a 3458A with such a sticker if I could. Dave Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please) ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Short term "standard" cell?
Hi Chris: I think it was my Heathkit VTVM that said to get a fresh AA battery and use it as a 1.52 Volt standard to calibrate the meter. An even better way was to use a Mercury coin cell since they were 1.35 volts and very stable. They were used for light meters and voltage references because of the very flat discharge curve. But when you are looking for many more digits of accuracy/precision then a battery may not be the best choice since pretty much everything will cause a variation. Maybe in order of importance: temperature, atmospheric pressure, humidity, impedance of measuring equipment, There are a few low cost voltage standards available where the maker has an HP 3458. For example by Geller and Malone: http://www.prc68.com/I/MTE.shtml#DCVR The care and feeding of chemical standard cells is such a pain and they are inferior to the modern electronic standards so they have become obsolete. The label on my Eppley shows 5 digits (4 printed and the last hand written). Note since there's liquid involved there is also an "Up" direction. http://www.prc68.com/I/Eppley.html#Standard_Cell http://www.prc68.com/I/Fluke332B.html -- Have Fun, Brooke Clarke, N6GCE http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Original Message In preparation of (hopefully!) Getting that fluke 332A running and sticker shock of what the 732A and similar references go for, I wonder about normal, every day alkaline or lithium batteries and their short term stability. Here's the half baked idea. A fresh, standard 1.5V, or 3V lithium, alkaline, or silver oxide button cell battery, or even an AA sized cell, measured by someone/some place with a known accurate precision meter. Invisioning 6 or so decimal places. Could that cell then be shipped, and used as a reference in another altitude? I haven't spent a ton of time looking, but haven't yet found anything on the web about stability of these types of batteries. Regards, Chris Sent from my SMRTphone ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Old v. New Volt?
Hi Frank: Thanks very much. I'm 99.999% sure the 332 is the instrument used. Not in the sense that it was accurate, but in the sense it could supply a voltage that stayed the same for a few minutes while it was read with the "old volt" 3458 then the "new volt" 3458. http://www.prc68.com/I/Fluke332B.html -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html The lesser of evils is still evil. Original Message Brooke, I had the very same encounter in 1989/1990. I received the new 3458A in November 1989, and only 1 month later, on 1st January 1990, the New Volt (SI-1990) went effective. As my instrument came directly from the U.S., the difference in calibration was 9.264ppm, which the instrument now was reading high. You may read my whole volt-nuts story related to this SI - change here: http://www.eevblog.com/forum/metrology/1000-my-(hi)story-of-the-weston-cell-of-the-volt-and-of-being-a-volt-nuts/. The 332B might not have been your reference standard, as its uncertainty is 10ppm / 60days only. Maybe you had a 732A, or a bank of Weston cells in your lab, otherwise this change could not securely be observed by a solitary Fluke 33xB/D. best regards Frank --- Die Bundesliga hat begonnen! Alle Tore, alle Ergebnisse, alle News: Pocket Liga jetzt im AppStore oder Google Play Store herunterladen - kostenlos! ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Initial Turn-On Fluke 332D?
Hi Mark: I hadn't thought of that, but have an ESR/Cap meter so will check it, Thanks. -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html The lesser of evils is still evil. Original Message You will probably need to replace a lot of the electrolytic caps on the circuit board... ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
[volt-nuts] Initial Turn-On Fluke 332D?
Hi: I just received a Fluke 332D from Fair Radio, but before I do anything is there some initial checks or a battery that needs attention? Just started reading the manual. -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html The lesser of evils is still evil. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] The Art of Electronics
Hi Orin: Thanks very much. I've got a copy of TS on order. Mail_Attachment -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Orin Eman wrote: Try searching for the TS V2 ISBN, 3540004297 on www.abebooks.com $40 for the International Edition from a somewhat reputable seller. Since this is an international list, I have no qualms about passing this on. Whether you can stand the almost transparent paper and smudgy ink is a different matter. Orin. On Sat, Apr 18, 2015 at 12:25 PM, Marv @ Home marvin.go...@comcast.net wrote: When AoE was released in 1980, the intended audience was electronics for a non-EE major. How this morphed into an engineering text shows how what is 'core' has changed. It had a friendly style, akin to having a instructor with you. AoE was best read in chapter sequence through the fundamentals, and higher chapters expect readers to know material from previous chapters without reference to it. On occasion it used concepts a jump forward but could be figured out by cross referencing its index. It was a semester course for us back in early 1980s. AoE v2 updated more in the digital domain with many corrected errata and typos from V1. I'd wait for V3 2nd printing or later, as typos from 1st printing are being reported as well as I read references to unpublished chapter Xs not in this printing. TS is an excellent text, if you already know the material and just need a refresher. It gets to the point quickly. Only 2 TS editions were translated to English; German has ?10+ editions. The only edition I ever looked at in print was v1, and it was $180+ in 1990s, compared to $50 for AoE new, or $20+ used. TS used in the USA is harder to find, and few V1 I've seen sell near $100+. Student or someone with a cursory interest, cost, writing style and similar breadth could be a tie breaker, AoE V3 sells for ~$100 delivered, and V2 $20-30 used. TS V2 from 2008 is ~$US260 delivered. At 04:33 AM 4/17/2015, Attila Kinali wrote: On Fri, 17 Apr 2015 08:24:38 + Poul-Henning Kamp p...@phk.freebsd.dk wrote: How does it compare to the gold standard of the TietzeSchenk? No idea. If you know a bit of german, get yourself a copy of it. You will love the in-depth explanations of the various electronics compontents. Also you can use it to knock out any burglar, should the need arise ;-) You have to remember that not everybody here are professional electronics people, I'm a software person who knows enough electronics to be useful without being dangerous, and I've certainly learned a lot from AOE3 over breakfast this past week. True that. The AoE gives at least a nice overview of quite a few electronics techniques. And probably not the worst thing you can start with, when you are new to electronics. That said, I kind of miss the amateur radio/electronics literature that was so abundant in the 80s. They really did a good job of introducing various circuits and how successfully build them if you don't have any professional equipment. Attila Kinali ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Checking an LCR meter
Hi Dave: The 4-terminal pair measurement method used on many of the HP (and other) LCR meters and impedance analyzers is much more accurate over many many decades of impedance value than network analyzers which are only accurate near 50 Ohms. This is explained in the impedance measurement handbook. In my mind the key to an accurate measurement is to know which of a number of impedance measurement techniques to use. The Z hdbk has contour maps showing the effect of frequency, impedance and accuracy for a number of different measurement techniques. http://www.prc68.com/I/Z.shtml#KeyDocs The other key idea is that LCR measurements are done on components without connectors and so there's the handling of the fixture parasitics. This is far from trivial. Again the Impedance Measurement Handbook is essential and the Measurement Accessories Selection Guide is very handy. And finally by making impedance measurements over a broad frequency range you can fit a model to the data instead of utilizing the simple series or parallel 2 component model that's standard in an LCR meter. This simple model may be fine for a lot of applications, but is not good for more complex cases. For example the model for a crystal resonator that's built into the E4915, E4916 E5100 is based on an S21 measurement and the use of a low-Z PI test fixture. What all these instruments have in common is frequency sweep and DSP IF processing. See my Crystal Equivalent Circuit web page for an example of a Z-transform (Z:T in upper left of screen shots) measurement. http://www.prc68.com/I/Xec.shtml Mail_Attachment -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Dr. David Kirkby (Kirkby Microwave Ltd) wrote: I have bought an HP 4284A precision LCR meter. This is an old model with a basic accuracy of 0.05% and covers 20 Hz to 1 MHz. Converting the specifications into determining the uncertainty of a measurement is nontrivial, but I think it reasonable to assume the uncertainty will always be 0.05%. Surprisingly the current precision LCR meter from Kesight, the E4980A (20 Hz to 2 MHz) offers the same basic accuracy. So while fairly old, the 4284A doesn't seem to be miles behind the current crop LCR meters from the top manufacturers. The recommended calibration period on the 4284A is 6 months, which would get rather expensive - on the current E4980A the calibration period is a more respectable 12 months. I am looking for suggestions on how I can get reasonable confidence in the instrument at reasonable cost, without returning it to Keysight every 6 months. I have a 3457A DVM, but mot much else in the way of precision low frequency equipment. It has 4 BNC connectors for Kelvin probes. I suspect that getting precision resistors and keeping them for a house standard might be worthwhile, but are looking for suggestions on the best approach. I will send it to Keysight once when it arrives to ensure that there are no faults on it, but I don't currently feel I can justify getting it calibrated every 6 months. Maybe I can make some stable standards, then measure them soon after the LCR meter calibrated been calibrated and periodically measure their values. Any suggestions about how to approach that? Dave ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] HP419A Meter Pegged to Right
Hi: My second oscilloscope was a new Tek 515 which I got for the student price and picked up from the Tek sales office on San Antonio Rd in Palo Alto. On the tour they showed me the washing booth where they used a water soap solution to spray wash the complete scope. There were no parts in the design that would absorb water. When washing semiconductor wafers after the DI water rinse they used an alcohol rinse then a compressed clean air blow off. The alcohol sucks up the water and what small amount that's left after the air evaporates quickly. Mail_Attachment -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html David C. Partridge wrote: And should you be prepared to remove the pots, you could run it through the dishwasher ... (if it works for Bob Pease, it works for me too). Regards, David Partridge -Original Message- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of ed breya Sent: 11 November 2014 07:44 To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP419A Meter Pegged to Right If you're talking about washing the board only, I'd say go for it. : : Ed At 07:28 PM 11/10/2014, you wrote: I'm trying to bring an HP419A back to life. : : Any votes for a water wash? Any better ideas? ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Finally got around to modifying my Fluke 845ab with LED's
Hi Chuck: Is there something special about the GR strobe tube that prevents you from using a more modern strobe tube? Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Chuck Harris wrote: Hi Mark, I have an itty bitty white led, probably called a T-1 size, and it glows dimly for a long time after you shut it down. They all pretty well have to. I think what you are seeing with your analyzer is the blue/UV component that drives the phosphor element. It will run just as fast as any old style LED. I also think that the blue/UV component, which is very bright, is what is driving Dallas's chopper. But enough on that. I wasn't trying to criticize, just make mention of something I noticed in my own work. Where I got to thinking of this is when I burned out the strobe tube in my G-R strobotach. Replacement tubes were in the $300 range, so I knew that would never happen, so I was thinking of making a solid state replacement using a handful of those wonderful little white LED's. They would certainly be bright enough, but I'm pretty sure the phosphor hang would make them unsuitable for stopping motion... your eye would see a blur instead of the razor sharp image you get with the strobe tube. -Chuck Harris Mark Sims wrote: I would probably use green or yellow LEDs, but the white ones should not be a problem. I built an LED analyzer/integrating sphere and one of the features is a circuit that optically measures the LED driver PWM frequency. It can also detect the minute variance in LED intensity from an LED driven by a 950 kHz boost converter. It also had no problems with a white LED driven at 4 MHz from a signal generator. You see the long persistence phosphors mainly in large lighting LEDs and not in small indicator LEDs. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] 34401A Why 10M ohm default i/p resistance?
Hi John: Because when measuring a source with a high resistance you get a different answer. Some W.W.II electronics specified 1 kOhm/Volt meters and if you used a VTVM you got the wrong results. If a test procedure specifies a 10MOhm input meter and you use a higher input Z then you may get wrong results. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html John Phillips wrote: so why do you care what the input is as long as you know what it is and how to make it do what you want? On Thu, Apr 10, 2014 at 1:16 PM, Brent Gordon volt-n...@adobe-labs.comwrote: Pure conjecture: So that the reading on the 34401A matches that on a $20 DVM. Or stated differently: So that the input impedance is the same as other DVMs. Brent On 4/10/2014 8:23 AM, Tony wrote: There is no suggestion in the specifications for the 34401A that the accuracy suffers by selecting 10G ohm input resistance on the .1 to 10V range so why would they make 10M ohm the default? I can think of very few cases where having the 10M ohm i/p resistor switched in is better for accuracy than not. On the other hand 10M is sufficiently low to produce significant errors on a 6 1/2 digit DVM for sources with resistances as low as 10 ohms. Measuring 1V divided by a 100k/100k ohm divider for example causes a .5% error - 502.488mV instead of 500.000mV. That might not be a problem but I wouldn't be surprised if this catches a lot of people out (including me) when not pausing to do the mental arithmetic to estimate the error. It's just too easy to be seduced by all those digits into thinking you've made an accurate measurement even though you discarded those last three digits. And if it's not a problem then you probably don't need an expensive 6 1/2 digit meter in the first place. It's a small point I agree but it can get irritating to have to keep going into the measurement menus to change it when the meter is turned on when measuring high impedance sources (e.g. capacitor leakage testing). It can't be to improve i/p protection as 10M is too high to make any significant difference to ESD and in any case there is plenty of other over-voltage protection. OK. it provides a path for the DC amplifier's input bias current, specified to be 30pA at 25 degrees C, but I imagine that varies significantly from one meter to the next, and with temperature, so not useful for nulling out that error. So why would they do this? ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
