[volt-nuts] fluke 332d
Hi, first my opinion about the Fluke 332/335: Those are very nice instruments, and you really need such instruments, if you really want to calibrate your DCV gear: Only having a 10V reference as 732A/B, or all those amateur grade 2.5 / 5 / 10V references won't help, as you always need the Cardinal Points (1000V, 100V, 10V, 1V, 100mV) for calibration. Therefore, those old 332/335 calibrators are basic instruments, to generate those voltage in first instance. You have to make sure, that they already contain the MOSFET chopper card (not the mechanical chopper). The reference also comes in two variants, either the older zener diode oven, or the Reference Amplifier version. Both are ok, but will not give more stability than about 10ppm/ 2months. There is an elaborate teardown/ripoff of the 332B/AF on EEEVBlog, where you can see additional stability parameters I have measured. http://www.eevblog.com/forum/testgear/fluke-332baf-in-the-slaughterhouse/msg393609/#msg393609 From those measurements, I really doubt, that old 332/335 calibrators will really get better over time. The reference is too simple to be principally stable, that begins with the simple oven, and ends by the non buried zener RefAmp. The cummulative drift over 40 years was about 500pm, so you cannot really state, that its stability had improved over time. The noise of the instrument presumably increased over time, as all the capacitors deteriorate, and also all the transistors loose their gain hfe. As simply a precision, stable high voltage power supply, a working 332D is very fine. The stability level is several ppm in any aspect. But as a standard, there's one important further problem: The 332D itself needs calibration, first linearity, second the range calibration. That strictly requires additional equipment, as a Fluke 720A, or a HP3458A, and a Fluke 752A. I have designed my own 100:1 / 10:1 Hammon divider, see EEVBLOG also, and for example, the 34401A is also capable to adjust the linearity. At least, I recommend to buy a Fluke 5440/5442. Its stabilities are ten times better in all aspects, and it features ultra high linearity by design,(my device: ~0.1ppm), and a Autocal feature, like the 3458A. The additional 1V and 100mV ranges have to be calibrated externally again, but 10V, 100V and 1kV can be calibrated from one external 10V source, similar to the 3458A. Frank ___ 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] fluke 332d and 732a... volt-nuts Digest, Vol 55, Issue 11
Aging is beneficial because it allows a part to physically relax into a shape that is appropriate for the way it is being operated... So, if a zener is going to be operated with no bias current, and at room temperature, sitting on a shelf for 30 years might be a plus... But not so much if the part is going to be run at 5ma bias, and a 55C operating temp. In that case, aging begins when the part is up to temperature, and power is turned on. -Chuck Harris new wrote: Question... do the old circuits get better with age? It would seem that the old standards would be much better now than they were when new. Is there any rule of thumb? Does a 20ppm/year circuit become a 10ppm/year circuit in say, 20 years? The industry uses voltage and temperature to simulate aging... so just 'aging' itself should work! The old survivors from the 70s, 80s and 90s should be very good! Willy ___ 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] fluke 332D
Hi gang, Thanks for the suggestions as to what type of calibrator to get. I mostly want a stable precision variable voltage reference for what I do, but a current/ ac voltage / resistance standard would be nice, so I can definitely see this being addictive! I have already found that out with other gear in my lab, you get a piece of gear and then after a while find you want something better! I did bid on a 5540b/af from the government liquidations recently, but the shipping costs to Australia are what limits my bidding amount for equipment that seems to be mostly in the USA, so I usually get outbid. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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] Fluke 332D
Dick wrote: I need a little circuit help here -- I'm looking at the schematic of the chopper amp, A5A4, and I'm trying to figure out if this amp is inverting or non-inverting for DC signals, that is from pin 6 input to pin 4 output. I'm looking at the simplified diagram on page 102 of the PDF manual, Fig 8-1, 3 of 3. The detailed circuit for the chopper is on page 104. Best, Dick Moore ___ 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. Inverting. Bruce ___ 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.
