LTZ1000 10v buffer

[KE5FX]

Very nice.  Could I ask where that enclosure came from?

[kj7e]

Very nice.  Could I ask where that enclosure came from?

Bud Industries TR-6100;
http://www.budind.com/view/Small+Metal+Electronics+Enclosures/TR+Series+Small+Cabinet

Got mine from these guys;
https://www.aiconsol.com/tr-6100-bud.html

[KE5FX]

Bud Industries TR-6100;

Thanks.  Looks very sharp (as it should for $175+)

[kj7e]

TiN,

Another TC sweep from 15C to 36C.  A bit slower and a more steady ramp.  Measured in uV deviation from 10.000000v.  The dip at 10K seconds was due to the shop door opening and cooler air entered the room.


Needless to say, I am very pleased with the results.  This has turned out better than I had hoped for.

[quarks]

@kj7e,
thanks a lot for sharing your very nicely made build 

[kj7e]

Thanks guys!

Finishing touches, I wanted to access the 10v trimmer with out affecting the internal oven temp, or at least have minimal effect on it;



McD's straw;

[kj7e]

Adjusted three days ago and not touched it since.  I know this needs to be measured in terms of months and years, but still its reassuring to see it not move even just after a few days.

[kj7e]

Long term update and test.

Going to put this here as it seems to show the stability of the 7 > 10v buffer more than the LTZ1000A KX reference.  The system has been powered on and at a continuous 35 deg C for about a year and a half.  In that time I have only seen about 0.3ppm drift between the DMM7510 and the 10v reference, no way to know which is drifting or if they both are, but being the DMM7510 uses the LTFLU-1 and they tend to drift in the opposite direction of the LTZ1000, its safe to say neither appear to be drifting much.

So I decided to do a test and see how sensitive the KX board and 10v buffer as a system are to small temperature changes.  My oven circuit  can be adjusted from 31 to 39 deg C via a 25t pot for about 0.35 deg C per turn.

Link to the oven circuit;
https://www.eevblog.com/forum/metrology/kx-reference/?action=dlattach;attach=412838

All measurements were taken with the DMM7510 and I held the room temp +or- 0.3 C as displayed in the 7510's internal CAL temp.  The meter was set to relative offset so I could easily track the change in uV.  Starting at the minimum temp of 30.8 C, I took a measurement increasing the temp by one turn then letting the reference stabilize for at least 30 min before the next measurement,  or about + 0.5 C per hour max.  I could not complete the entire test in one sitting, it was compiled over two day.  I only hand recorded the results, no fancy plots or charts, sorry.

The results only show the limiting factor is the DMM7510 and my lab temp stability.  The KX board and 10v buffer simply seem unaffected between 31 -39 C with a max measured difference of about 1 uV or 0.1 ppm.  I can see initial + voltage swing as the oven heats, but then settles down right where it started, same when the oven cools I see a - swing but then comes back up as the temp stabilizes.  The oven holds the temp to a stable 35 C + or - < 0.3 with an ambient temp range of 15 - 30 C, so I'm more than pleased.

[ghg]

Hi

Just came across this old topic, but I have to ask.
Is there a way to do a graph including V AND temp using the 7510 ?
Would logging make much easier.

BR Gary from Vienna