This thread is about the investigation on ...
Well, no words about it yet. It's up to your guess. Here are the first pictures of some parts a friend of mine currently fabricates for this project. The next pictures will follow soon and after a while you will get an idea of what this will end up in.
Either resonant cavity or oven...
Hello,
looks more like one of those zero ohms resistors or a 4 wire shunt.
with best regards
Andreas
Hmmm,
It's in the metrology section, high thermal mass enclosure, structurally stable..... Resistance standards? No fixing holes on the top surface though and they look finished. Something potted? Strange if so.
I bet its a resistance standard
I bet its a resistance standard
+1 Metrology individual resistors look similar to this.
Resistor tempco test boxes?
I'm gonna build some too, as my current TEC jig used for LTZ reference module test is just
too painfully slow for TCR test.
Come on branadic, give us a break - is there some kind of lid???
My guess is that they will laser weld the lids and install kovar leads or some hermetic connector out of the sides.
There is a lid on top and some feedthrough capacitors at the sides.
Too much pieces for a simple investigation ...
Inviato dal mio Nexus 6P utilizzando Tapatalk
RF directional coupler for a VNA...
I would guess voltage reference using low noise chinese zeners or oil filled resistors
hermetic resistance?
If you look closely there seems to be a naked bulk metal foil resistor inside the box.
4w for resistor, and 2 for thermistor or RTD....
hm...
Worth noting that the 4-wire feedthrough for the main resistor is actually not necessary. Simply calculate how much the very short resistor copper wires affect the total temperature coefficient.
The SR104 uses 2-wire feedthrough but there is also 15 cm 2-wire cabling from the feedthrough to the binding posts (2w/4w interchangeability was important at the time it was designed).
I'd buy few samples of such neat boxes for my unhappy foils
If you look closely there seems to be a naked bulk metal foil resistor inside the box.
Good observation
Yes, it is a hermetic case for Vishay VAR resistors in 4W connection and an additional PT1000, using PCap01 a like chips to measure and digitize temperature. The case will be filled with Galden, to avoid humidity effects. The lid is soldered to the bottom part.
It's just to find out how Vishay VAR can perform. Because at the institute I work for our main topic is packaging of integrated circuits. What I've learned so far is, that every highend sensor can perform bad if package and assembly is bad. So take the naked part, use an adequate packaging technology and the part will perform much better.
Hello branadic,
one question arises to me.
Does Galden expand with temperature?
How is the relation of the expansion coefficient against the housing.
Or is there some pressure relief planned?
With best regards
Andreas
I plan to use something like LS230, so no big deal within normal operation.
Hi Branadic.
Could you consider to use more sensor like BME280
So you can measure humidity and pressure
why galden? just because its handy? I would think others such as fluorinert or silicone transformer oil (ok, soldering issues, but thats after the fact anyway) are more itended for that purpose, and partly also show higher insulation resistance. I do not know galden very well, other than its used for VPS, maybe you can give us some details why you selected it.