Fluke 732A + Fluke 752A

[TiN]

That was most boring bid I had. Just put up 1330 and went to sleep, hoping that I will not win it  . Well hopes payed off, I don't have two more projects in the list.
Hope we will see the owner here soon enough.

[Bill158]

Yeup, that's kind of like the brass tube + plastic rod tool we made (similar to the real Fluke version we've seen) except at the business end the blade would be recessed back into the tube a bit, maybe an 1/16~1/8" or so. 

The GC 8276 has exactly what you describe on one end with the blade recessed slightly.  On the other end, as you can see, is a blade that is exposed.  Once I get the 8276 recessed blade engaged with the pot I can just leave it in position until I am done adjusting.  Of course there is always a little "hysteresis" when adjusting the 10 volt pot.  So I usually give it a very small turn opposite ( 1/16th ) to the direction I was turning and then give it at least 1 hour to settle down before pulling the tool out.  Don't forget to reverse the leads from the UUT and the "certified 732A" and then take the readings from the null meter and then algebraically add the two readings and then divide by 2.  There is always a slight "offset" between the forward and reverse hookups.  Read the 732A manual.  Other FLUKE application notes use a specially constructed ( no details given ) "reversing" switch ( dd_2_ncs100.pdf ) to change the HI and LO inputs to the null meter.  I use a 3458A as my null meter.  Some people will say that the 3456A/3458A are not appropriate for this purpose but I have gotten excellent results as long as I do a reversal of the leads to the two voltage references ( 732A/732B ) 100 PLC 40 readings and STAT MATH on.  Read the MEAN at each reversal, add the readings and divide by 2 (of course observing the +/- signs ).  The 732B manual uses a FLUKE 8506 as a null meter in one procedure.  This technique allows you to measure ppm ( tens of uVolts ) differences between the two 732As accurately.  I haven't done an adjustment in years.  I just track the differences and plot them.  See the NIST note "designsforsurvei430eick.pdf".  Also FLUKE "CALIBRATION - Philosophy in Practice", first edition, chapter 9.  While all of this was written for Standard Cells it works just as well for Solid State Voltage References such as the FLUKE 732A/732B.  Of course you need a bank of at least 4 references ( i.e FLUKE 734A or 4 ea. 732A) or equivalents.
Bill

[MisterDiodes]

Sounds good on that tool!, I didn't see that detail in the product photo.  If ours fizzle out we'll order some.  We use real null meters because we have them and much less added noise and quicker to use, but a 3548a / 56a can work also as you have it set up.  Yes, good advice to always keep reversing the leads (then difference divide by 2) no matter what "null meter" you use to compensate for whatever other errors in the system.  That's how it's done.

We don't normally adjust 732's either, just send them to Fluke for Calibration as "Measure Only - Functional Test" and they haven't had adjustment in years - and we know exactly what they are for voltage.  Probably don't need adjusting anyway if they are cared for, but you do want that drift record - if you see that start to change that can be a head's up that a unit is starting to drift.  The only time we'd do an adjust locally is if we're fixing up a new old unit that needs to go into to service - you can't have too many in the cal rotation.  But it's good to do a local adjustment first before sending an "unknown history" unit to Fluke so they don't get worried that it's too far out.

[0.01C]

I used Prokit's 1PK-606A (US$2) to adjust the pots.

[MisterDiodes]

Good!... Just one thing: We've got one early 732a that won't take a 3.3mm shaft though - if that is what I see as OD of the tube.  It would be more like 2.9mm max. diameter.  That tool would work on the later ones though.

[CalMachine]

Check out my stick 

[0.01C]

Check out my stick 

same?

[martinr33]

My AAF 732a has been settling in for a couple of years now, and measures (against my friend's units) at 10V + 49uV. So I call that one stable. As happens, I have picked up a few more, and they all seem to be settling in at this level of stability.

[notfaded1]

By the way if someone needs the adjustment tool for a sweet price I needed one and found some super cheap here:

https://www.ebay.com/itm/GC-Electronics-8276-Mechanical-Alignment-Tool-Butyrate-6-1-8-Length/293097384911

Free shipping awesome deal and it works like a charm!  So good I bought two to have a spare.

Bill