[volt-nuts] FS: NOS Agilent 34401A
Hello. Saturday I bought a 34401A. I was interested just in another instrument but the seller insisted to sell them only together, so I had bought this one also. The condition is very good, it has been sold to me as NOS but I cannot be sure. However, I checked calibration number and it's 35, means it has only the initial factory calibration, date April 11 2001. It's complete with rubber and handle, it's clean, without any scratch, display is bright, and everything is like you should expect from a, if not really NOS, lightly used instrument. I would keep it, if I had not already other two of them in the same condition in my lab, plus a switch unit with the same multimeter inside... so it will not end on an auction site: I offer here to the group and if no one is interested, I'll keep it. It's a US made Agilent marked version, with red and black binding posts (not the previous all red ones) but still square power button and rectangular shift key, software revision "11/05/02". Original paper User's guide and Service guide are included, as well as a power cord, CD with Intuilink software, original test lead kit still in the bag. The calibration certificate with test report is missing, and I don't have original box. All the rest of the standard accessories are there. Of course, calibration is absolutely expired. I have not enough equipment to verify if it's still inside limits in every range; besides that it seems to work correctly. Other questions, just ask. Note: it's identical to the other two I have, except that they have initial calibration two months earlier and serial some thousands lower. I didn't upgrade their firmware (and I don't think user can do it) thus the software revision date late than calibration is evidently normal for this batch. I can eventually ship everywhere but I prefer to ship inside EU. You can send your (reasonable) offers via mail. Best regards, Andrea Baldoni ___ 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] low emf solder
On Sat, Oct 29, 2016 at 03:27:49PM +0100, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > Perhaps the person who was making the measurements on the solder, could try > making a thermocouple by welding two bits of wire taken from different > sources. I guess the problem would be preventing any impurities entering > the weld. A quick Google suggests one needs argon gas when welding copper. Hello David. I can test two different wires even without welding them, eventually. This will not make a very durable thermocouple but if I clean them to avoid to have a oxide layer, the result should be the same for the sake of measuring thermal EMF. I expect to have a very low signal to measure though. I must think to experiment setup. Best regards, Andrea Baldoni ___ 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] Thermal EMF of solder alloys - upd. october 2016
Hello. Thank to the contribution of Dan Kemppainen, Herbert Poetzl and Andreas Bergman, I had the opportunity to test more alloys. As before, a really low EMF (< 2uV/K) hasn't been identified. Measurements have been done between water ice point and boiling point with Agilent 34401A. I don't expect the curves be linear, but here it's assumed they are. All experiments have been repeated. Copper - Sn96.5/Ag3/Cu0.5 -> 3.35uV/K (first experiment) Copper - Sn96.5/Ag3/Cu0.5 -> 3.38uV/K (second experiment) Copper - Sn95.5/Ag3.8/Cu0.7 -> 3.22uV/K (first experiment) Copper - Sn95.5/Ag3.8/Cu0.7 -> 3.25uV/K (second experiment) Copper - Sn60/Pb40 -> 3.34uV/K (first experiment) Copper - Sn60/Pb40 -> 3.35uV/K (second experiment) Copper - Pb92.5/Sn5/Ag2.5 -> 3.02uV/K (first experiment) Copper - Pb92.5/Sn5/Ag2.5 -> 3.05uV/K (second experiment) Copper - Sn99.3/Cu0.7 -> 3.43uV/K (first experiment) Copper - Sn99.3/Cu0.7 -> 3.45uV/K (second experiment) Copper - Sn96/Ag4 -> 3.33uV/K (first sample, first experiment) Copper - Sn96/Ag4 -> 3.32uV/K (first sample, second experiment) Copper - Sn96/Ag4 -> 3.28uV/K (second sample, first experiment, thanks to Andreas) Copper - Sn96/Ag4 -> 3.24uV/K (second sample, second experiment, thanks to Andreas) Copper - Sn97/Cu3 -> 3.48uV/K (first experiment) Copper - Sn97/Cu3 -> 3.44uV/K (second experiment) Copper - Sn88.6/Cu1.8/Ag9.5/Au0.1 -> 3.05uV/K (first experiment, thanks to Andreas) Copper - Sn88.6/Cu1.8/Ag9.5/Au0.1 -> 3.04uV/K (second experiment, thanks to Andreas) Copper - Sn95.5/Cu0.7/Ag3.8 -> 3.28uV/K (first experiment, thanks to Andreas) Copper - Sn95.5/Cu0.7/Ag3.8 -> 3.27uV/K (second experiment, thanks to Andreas) Copper - Sn42/Bi57.6/Ag0.4 -> 4.43uV/K (first experiment, thanks to Herbert) Copper - Sn42/Bi57.6/Ag0.4 -> 4.46uV/K (second experiment, thanks to Herbert) Copper - Sn100C (Sn-Cu-Ni+Ge) -> 3.45uV/K (first experiment, thanks to Dan) Copper - Sn100C (Sn-Cu-Ni+Ge) -> 3.41uV/K (second experiment, thanks to Dan) Copper - Brass -> 3.30uV/K The best one keeps to be the Pb92.5/Sn5/Ag2.5, the best between the lead free ones is the Sn88.6/Cu1.8/Ag9.5/Au0.1. If someone has other alloys to suggest me to test I'll be happy to do it. I'll be very happy to pass all the samples to a fellow who wish to repeat the experiment, provide that he/she will post results here and in turn, will pass everything to the second one who will do the same. Best regards, Andrea Baldoni ___ 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] Calibration of 34401A
On Wed, Oct 12, 2016 at 09:54:01AM +0100, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > He sold a Agilent 34401A multimeter which the customer said is out of > specification and can not be adjusted. > > Quickly scanning the measurent results, the meter is not showing results > with any huge errors (say 1%), but which (if any) range it is out of > specification I don't know. Unlike the Keysight calibration certificates I > have seen, the measurement results doesn't show the upper and lower limits > for the specification of the meter, so one can not tell from a quick > glance if the meter is out of specification. One would need to study the > detailed specification. In the service guide (document 34401-90013) you will find the full list of performance verification tests with upper and lower limits. You will need a calibrator to verify them (except zero). The DC 10V range accepted error after 1 year from calibration is +- 400uV (+-190uV after 24 hours, +-250uV after 90 days), so -910uV are in effect not inside limits and the instrument needs calibration. Best regards, Andrea Baldoni ___ 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] Thermal EMF - again more results
Hello. Thank to the contribution of Dan Kemppainen and Herbert Poetzl, I had the opportunity to test more alloys. As before, a really low EMF (< 2uV/K) hasn't been identified. Measurements have been done between water ice point and boiling point with Agilent 34401A. I don't expect the curves be linear, but here it's assumed they are. Copper - Sn96.5/Ag3/Cu0.5 -> 3.35uV/K Copper - Sn95.5/Ag3.8/Cu0.7 -> 3.22uV/K Copper - Sn60/Pb40 -> 3.34uV/K Copper - Pb92.5/Sn5/Ag2.5 -> 3.02uV/K Copper - Sn99.3/Cu0.7 -> 3.43uV/K Copper - Sn96/Ag4 -> 3.33uV/K Copper - Sn42/Bi57.6/Ag0.4 -> 4.43uV/K (thanks to Herbert) Copper - Sn100C (Sn-Cu-Ni+Ge) -> 3.45uV/K (thanks to Dan) Copper - Brass -> 3.30uV/K The best one keeps to be the Pb92.5/Sn5/Ag2.5, the best between the lead free ones is the Sn95.5/Ag3.8/Cu0.7. If someone has other alloys to suggest me to test I'll be happy to do it (I have just ordered the Sn97/Cu3 to see if higher copper content is relevant). I'll be very happy to pass all the samples to a fellow who wish to repeat the experiment, provide that he/she will post results here and in turn, will pass everything to the second one who will do the same. Andrea ___ 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] Thermal EMF - more results
On Wed, Jul 06, 2016 at 03:42:18PM +0200, Herbert Poetzl wrote: > Any plans on testing Sn42/Bi57.6/Ag0.4 ? Hello Herbert. I don't have any source of it. My supplier (Heraeus) hasn't it, at least, it wasn't included in the list of samples they are able to give me on request. If you have it and you could ship it (a meter of 0.5-1mm wire or so would be sufficient for me and I will give it back after), I will be happy to test it. Today I received the Sn99.3/Cu0.7 and I will post result soon. Best regards, Andrea Baldoni ___ 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] Thermal EMF of common solder
On Sun, Jun 26, 2016 at 09:07:38PM +0100, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > Please excuse my ignorance, but how do you mean the thermal EMF of solder? > Do you not need another metal, such as copper to make a junction? If so, > you are measuring the emf Hello David. Yes, I measured it with copper, I mentioned it on the table of results. Best regards, Andrea Baldoni ___ 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] Thermal EMF of common solder
On Sun, Jun 26, 2016 at 11:55:56AM -0500, David wrote: > I have a spool of something from Kester that may be Sn96Ag4 but it is > only marked Sn96. Sn96 could also be the trade name for the Sn96.5/Ag3.5. NameComposition SAC101 Sn98.9 Ag1.0 Cu0.1 SAC105 Sn98.5 Ag1.0 Cu0.5 SAC125 Sn98.3 Ag1.2 Cu0.5 SAC125+Ni Sn 98.25 Ag 1.2 Cu 0.5 Ni 0.05 SAC266 Sn96.8 Ag2.6 Cu0.6 SAC300 Sn96.95 Ag3.0 Cu0.05 SAC305 Sn96.5 Ag3.0 Cu0.5 SAC307 Sn96.3 Ag3.0 Cu0.7 - Sn80.8 Sb18 Ni1.2 - Sn98.9 Ag1.0 Cu0.5 SAC350 Sn96.45 Ag3.5 Cu0.05 SAC387 Sn95.5 Ag3.8 Cu0.7 SAC400 Sn95.95 Ag4.0 Cu0.05 SAC405 Sn95.5 Ag4.0 Cu0.5 Sn96Sn96.5 Ag3.5 (non lead free:) Sn63Sn63 Pb37 Sn62Sn62 Pb36 Ag2.0 Sn10Sn10 Pb90 The Sn96/Ag4 seems to be for the food service equipment, refrigeration, heating, air conditioning, plumbing and not common in electronics. The Sn10/Pb90 is also known as low EMF but being non RoHS I don't think it's easy to find it (though not too dangerous to work with). I don't know if the .5% Ag between the 96.5/3.5 and 96/4 would change much in the EMF, I'll test it and report, if I find both. Best regards, Andrea Baldoni ___ 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] Thermal EMF of common solder
Hello All. I measured the thermal EMF of two common solder, the lead free Sn96.5/Ag3/Cu0.5 and the old Sn60/Pb40. I have ordered a spool of Sn96/Ag4 (the recommended low-thermal-EMF replacement for cadmium based one) and I will post the result for this too. I could probably find also Sn97/Ag3 and Sn97/Cu3 if it's reasonable to check them; I accept suggestion on what else to try between the RoHS complaint ones. Copper - Sn96.5/Ag3/Cu0.5 -> 3.4uV^C Copper - Sn60/Pb40 -> 3.3uV^C Best regards, Andrea Baldoni ___ 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] Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter
On Sun, Jan 24, 2016 at 07:54:34PM +, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > I've got a HP 3457A 6.5 digit multimeter - S/N 2703A04579. It's working > fine, but I'm aware the battery must be at least 11 years old, as I first > bought the meter 11 years ago. I suspect its due for a change. I'm trying > to find a *reputable* source for a replacement. I want to avoid eBay, due > to the number of fakes on there. Hello David. If the Panasonic replacement is good, you can buy the equivalent Varta 06127201301 from RS (their code is 240-9437). http://uk.rs-online.com/web/ Best regards, Andrea Baldoni ___ 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] Fall of SRAM voltage in a 3457A without external power
On Mon, Jan 25, 2016 at 11:46:19AM +, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > V). and well above the 2.0 V needed to hold the SRAM contents. Assuming the > SRAM takes a constant current one would expect the voltage to fall linearly > with time. If so, it would take 46 minutes to fall to 2.0 V even without > battery power. Hello David. I think you can probably assume the SRAM idle current be proportional to e(k*v) (an experimental k for some microcontrollers with SRAM I used was 0.44), so it should decay even more slowly. Best regards, Andrea Baldoni ___ 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] Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter
On Mon, Jan 25, 2016 at 04:52:56PM +, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > It is the same general type, but the pinout is wrong. Mine has two radial > pins, not 3. That will not fit. Sorry, I understand now it's a 2/3A, much bigger. The original LX1634 (LX16/34) is a Li-SO2, 850mAh, 2.8V nominal, 3V open circuit. Current SAFT model is "G 32/3". Here is the datasheet http://www.saftbatteries.com/force_download/G_323.pdf I saw the code "G 32/3.4" should point to the version with PCB pins, but I wasn't able to find the original datasheet and any EU source. If you can accept to change the chemistry to a Li-MnO2, you can use the Varta 06237501301 from the supplier I suggested. This is a 2/3AA, same height, thinner, with radial leads like a capacitor, so you should find the way to fit it. Another idea could be use a holder and put a (very easy to find everywhere) CR123A. Best regards, Andrea Baldoni ___ 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] Again about Keithley triax connectors
On Mon, Nov 30, 2015 at 06:17:34PM +0100, Andrea Baldoni wrote: > I managed to get two triax male connectors, extinct brand "Specialty > Connector Co., Franklin, Indiana", vintage 1990, kind to be screw assembled. > The part code is 30P100-1. I also have a triax 2-lugs male/triax 3-lugs > female adapter, part code 30A103-4. Further research revealed they have been sold by Keithley as the CS-141 connector. I still didn't find assembly instructions. Best regards, Andrea Baldoni ___ 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] Differential amplifier >=1Mhz
On Mon, Nov 23, 2015 at 12:35:29PM -0800, Pete Lancashire wrote: > The problem is a stand alone diff amp is going to be a low volume thing to > sell At this point I think I'm trying to solve a problem everyone (except in very rare cases) solves in another way, so it's me I'm wrong. Anyway thank everyone for all the suggestions; I set up the auto notify for everything and let's see. Just there are so many "strange things" around like the XL741 that are of very dubious sell http://shop.evilmadscientist.com/productsmenu/762 that what I think is a useful item had not to be so rare. By the way, if I can open-design one, what features should it have? Anyone interested? Best regards, Andrea Baldoni ___ 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] Differential amplifier >=1Mhz
On Mon, Nov 23, 2015 at 07:06:59PM +, Mark Sims wrote: > Maybe a Tektronix AM502 module and the single slot TM501 mainframe? Hello Mark. Yes, the AM502 is the thing I am searching, but they are not very cheap for a 1977 vintage, in particular adding the mainframe. It's possible that in 38 years no maker did anything like? Looking better, all other modules I saw aren't equipped with front panel output, because are in effect vertical oscilloscope amplifiers and thus the output is on the backplane. And they are not cheap also. Best regards, Andrea Baldoni ___ 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] Keithley triax cables, 6011 and 1506/1507
On Sat, Nov 21, 2015 at 12:43:07PM -0500, Todd Micallef wrote: > I did purchase a MS3106-E16-11P that fits it perfectly. The original > connector appears to be gold plated(?) and the MS connector is silver > plated. It is unknown which "copper alloy" is in the MS contacts. I have > had other projects so I have not had time to determine how well the MS > connector compares to the original while shorted. Hello Todd. Thank you, I will buy the connector, then perhaps in the future I may be able to find the original one. Brian suggested the 1507A cable, it's in effect marked as discontinued by some sellers while you can still order it from others, but anyway it's about 500 USD and actually it's too much. > There is a Keithley 140 up for sale on the usual auction site. I cannot > find the manual for it, but maybe the seller will be willing to part it > from the meter? It has been listed for quite a while. It would be a matter > of the seller confirming the part number stamped on the edge of the > connector. The seller answered me and he said the cable goes with the meter... > As for solder, Keithley recommends Sn/Ag4 solder for the 2182A connectors. I have the usual SnAg3Cu0.5 and in everything I can find there is still 0.5Cu. However I saw that the SnAg4 is used for the assembly of solar panels strings so I know where to ask. > I am sure that discussion (low thermal solder) has been had here in another > thread. I think in the past has been concluded that an adequate replacement is Sn10Pb90 but it's probably harder to find than SnAg4 because of RoHS. I will try to crimp the wire and avoid the matter completely. Best regards, Andrea Baldoni ___ 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] Keithley 181, 220, 617 ROM dumps
Hello. In the process of cleaning and controlling the instruments (some capacitors need to be replaced and so on) I made a dump of the ROMs of Keithley 181 nV, 220 Is and 617 electrometer. If someone need them, just ask. By the way, they have very little firmware for actual standards. Best regards, Andrea Baldoni ___ 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] nA advice
On Fri, Nov 13, 2015 at 01:56:19PM -0500, Charles Steinmetz wrote: > Rob wrote: > > >50V across 5GOhm is 10nA. Put a standard multimeter's 10MOhm input in > >series and > >you have 10mV per nA reading. Anything below 100mV is pass. Yes, Rob. I late also thought about it that way while answering to Todd. In effect I wasn't used to think to DMM the way it was for galvanometers :) > Also, quite a few of the Fluke portable and handheld DMMs from the last 35 > years or so (including the faithful old 8050A and the "80-series" DMMs) > measure conductance (1/R) with a resolution down to 0.01nS (= 100G ohm). > There are lots of them with this capability on the used market for $10 and > up, and several are still available new (but not for less than Eu100, to my > knowledge). Charles, I own two new generation fluke portables (one is a 177 and the other is the cheap 15B) and no one has this characteristic anymore, who knows why, but it's very interesting. According to http://www.fluke.com/fluke/uses/comunidad/fluke-news-plus/articlecategories/rd/the%20mho%20that%20become%20siemens the new multimeters with conductance measure are 87V and 189. No one fits the 100 EUR range by far, but I can buy an used 80-series one, they are very cheap and I can bring them on the field while I would like to let the 34401A in the lab. I saw the 8060A resultion is only 0.1nS; I cannot find the specs of the 8050A (neither the user's manual). Which one do you suggest? Best regards, Andrea Baldoni ___ 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] nA advice
Hello! I would like to measure insulation resistance of some defective load cells. The measurement should be done with no more than 50V and the full scale reading should be >=5Gohm. Accuracy of +-10% is enough (in fact it could suffice just to check if it's >=5Gohm or not). I have not been able to find a ready made instrument that could do this within a reasonable price (100 EUR); the normal insulation resistance testers go much high with the probing voltage (on the purpose, but this also lighten much the requirements on the sensitivity of the meter). It could be as simple as a led indicator "pass/fail", but at this point, why not to build a good frontend for a multimeter, so it could be much more useful? There are many way to do this and also many ready circuits (like the null detector in the mini metrology lab by Conrad Hoffmann) or in the AoE, but instead of making it from scratch, someone knows if there is something already made (or a kit)? Best regards Andrea Baldoni ___ 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] Curious overvoltage event
On Mon, Aug 10, 2015 at 10:22:47AM -0400, Chuck Harris wrote: If the mains supply hangs around in certain brown out voltage ranges, it can fool the start up control circuitry into exceeding the ratings on the bootstrap circuitry, or the inrush limiting circuitry, and toast parts. Hello Chuck. Thank you for your idea. As I wrote later, I was wrong and the involved circuitry is another one; even if at this point it could be not a mains-related failure, it's still a curious thing that two PS failed in exactly the same way in such little time. Best regards, Andrea Baldoni ___ 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] Curious overvoltage event
On Mon, Aug 10, 2015 at 03:34:59PM +0200, Andrea Baldoni wrote: interactive UPS burned out. I opened it, and the chain of resistors and diodes giving the startup power to the control IC UC3843 arched and the IC itself exploded (more details on the circuit later on request, I still didn't reverse engineer it). I was wrong, it's not the chain of resistors for startup. There are two 900V MOSFETs, SD paralleled, each one with a 1N4148 and a 330 ohm resistor (SMD) in parallel to get gate drive from a common line, coming from the exploded UC3843. Obviously the transistors actually are SD shorted (one is also G shorted, the others have various resistances). The sources are connected to GND through a 0.17 ohm power resistor, now ashes. It seems that the starting event could have been a transistor drain-to-gate short, that itself, assisted by a back EMF from the transformer, made gate arching to source pads on the PCB (connected to GND) and all the rest. At this point, despite the fact that another customer (other 20-something Km the other side) just called because his router power supply burned yesterday, probably it was just a coincidence. What do you think about? Best regards, Andrea Baldoni ___ 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] The Art of Electronics
Hello. In the case someone missed the new, after years of waiting, the third edition of the book in the subject is out! I'm a true fan of the second edition and I'm sure I will not be disappointed by the new one; I should receive it in the beginning of the next week so if someone is interested in details, feel free to ask. Best regards, Andrea Baldoni ___ 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] Agilent 34970A (34401A) self test error 606
Hello all. Following the thread on time-nuts about the ebay seller yixunhk and afraid to have been a victim of their way to do business, I decided to thoroughly test an Agilent 34970A unit I bought from them some years ago in almost-new shape and practically never used since then. The 34970A is a data acquisition unit with builtin multimeter identical to 34401A, with some math function absent in 34401A like the direct measurement of RTDs. The ADC is a Multislope III and you may find it in other instruments as well, like the E3631A power supply. I took the opportunity to use it to watch the temperature of an experiment, so I connected a 100R platinum RTD and begun. After an hour I noticed a sudden 10x or more increase in noise, so much that the measure could not be read easily while was still to the tenth of C just a moment before. After having excluded cabling pickup, sensor defects, and so on, I launched the self-test and got Error 606. I left the instrument on for a full day, to let it stabilize and maybe dry up from the moisture, even if it has always been kept in the lab, and repeated the test with the same error. The test imply a power cycle and the error didn't wanished just with that. Today I was ready to do further checks, but after a cold start, the noise is normal (I think, being +-17PPM worst case in the two wire 100R range measuring a 100R precision resistor at 6.5 digits resolution) and the self test pass. (the 34401A noise with the same resistor is much better, +-2.5PPM worst case, but I expected this because of relays in switch units and wiring issues in my setup of the 34970A) The Error 606 description is: Rundown gain out of range - This test checks the nominal gain between the integrating ADC and the A1U205 on-chip ADC. The nominal gain is check to +-10% tolerance. Someone ever had such kind of fault? Do you think that the problem may come from the reference LM399 and/or reference amplifiers, the integrators, or the on-chip ADC? (in that case probably the instrument could not be repaired at component level) Someone has the detailed description of the Multislope III patent? It seems it's exactly what's described in the HP Journal - April 1989, page 10, figure 4, about Multislope Runup, using the on-chip ADC instead of a comparator to extract some more bits of resolution. I have also some questions about the schematic diagram of the 34970A: the componente marked never_load (page 237 of the service manual, A/D converter schematic, component R445 for instance) aren't populated on the board or the meaning is another? Also: the precision of the runup setting current (by 100K resitor part of the array U102-E) isn't lost by dividing it through non-matched R440+R443 ? Best regards, Andrea Baldoni ___ 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.
