On 20 August 2015 at 02:38, Todd Micallef <tmical...@gmail.com> wrote:
> Here is a DIY guide to making some lab standards. It is detailed with some > component values. > > > http://nopr.niscair.res.in/bitstream/123456789/4848/1/JSIR%2065%286%29%20510-513.pdf > As I wrote before, I think this is of dubious use, as you are not making an inductor, but just making the meter indicate there's a low Q inductor, by using the 4-wires in an incorre > > On Wed, Aug 19, 2015 at 8:48 PM, Dave M <dgmin...@mediacombb.net> wrote: > > > Here's a paragraph from IETLab's web site on how their inductance > > standards are made: > > > > "Each standard inductor is a uniformly wound toroid on a ceramic core. It > > has a negligible external magnetic field and hence essentially no pickup > > from external fields. The inductor is resiliently supported in a mixture > of > > ground cork and silica gel, after which the whole assembly is cast with a > > poƫting compound into a cubical aluminum case." > > > > Sounds like their objective is to isolate the winding from as many > > external influences as possible. Of course, the same couild be said of > any > > physical or electrical standard. > > > > Cheers, > > Dave M > > > > > > > > > > Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > > > >> I was looking to make some inductors that I can use as a sanity check > >> for > >> my HP 4284A LCR meter. I don't too much care what their values are, > >> but I want them to be stable with time. Any suggestions about the > >> best way to > >> make or buy them? I'd like values in the range of 1 nH to 100 mH. > >> > >> The LCR meter has 4 terminal Kelvin connections, with 4 x BNC sockets > >> on a 22 mm pitch. > >> > >> The meter is at Keysight at the moment being calibrated, along with a > >> free software upgrade they are kindly providing. So I'd like to > >> measure some inductors when it comes back, and track their values > >> over time, to see if the meter is drifting. > >> > >> The meter covers 20 Hz to 1 MHz, and has a basic uncertainty of > >> 0.05%, so ideally I'd like to keep inductor changes to less than > >> 0.005% over a year, so the inductor is an order of magnitude better > >> than the meter. Maybe that is not practical. As I say, the absolute > >> value is not important, since I only want a comparison. > >> > >> The calibration costs on this meter are not too bad (£207 GBP), but > >> the calibration interval is 6 months, which is a bit annoying. I'd > >> rather not > >> be sending it off every 6 months if I can satisfy to myself it has not > >> drifted too much. Luckily I don't need to satisfy anyone else. > >> > >> 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. > _______________________________________________ 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.