Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

This is how to pack a delicate piece of TEA gear for shipment. These photos are of the outer carton, the actual packing  and the meter itself and its first power up, later I'll tear it down and snap some more pics, I;m excited, have never seen inside one of these before, and I'm wondering if has any similarities to the 4503 and the 1905A, one thing I can say is that when compared to the TTI counters and function generators, this 1906 is heavy, it as heavy as my HP3466A meter and that even has a SLA battery inside, so my fears of it wandering over the bench while being used were totally unfounded.

[mnementh]

Regarding the safety of EV's and their batteries, there is no real safety advantage between Cylindrical and Prismatic packs. Cylindrical have some minor cooling advantages, but getting the same power density as prismatic packs is difficult. Mechanical strength is important, but the electronic monitoring will react well before any mechanical component has failed. The batteries are monitored (voltage, current, Charge state, State of Health and temperature) on the cell pack level, so even if a single cell shorted, the system will react in microseconds and like any ICE vehicle, the entire power source is also cut as soon as any crash is detected.

As for the driving experience, as mentioned above, it's the torque curve that people notice at first. People are used to an engine needing time to react, especially if they drove a diesel up to then. The motor definitely isn't an ON/OFF situation, it's just like any variable motor control.

I won't comment on the environmental or infrastructure aspect, that's politics not engineering and will be different for every country.

McBryce.

* This information/opinion doesn't come from a report, I've worked in EV and EV Battery development for almost 20 years, including work on the Prius.

While I obviously don't have your experience with EV PS, I do understand what you're talking aboot from my own work with telemetry on LiPo batteries and model aviation power systems. The problem here is not the electronic monitoring; it is the concentration of material in a single envelope. Well, it is the monitoring; in that counting on electronic monitoring to protect you is no excuse for not making the mechanical packaging as safe as possible, and mechanically, prismatic cells are much more material in a single package with a much greater tendency to rupture.

Same reason we pack dynamite into cylindrical sticks, and we consider a brick of C-4 in a box much more dangerous than an equivalent capacity of dynamite stored appropriately. made dynamite by diluting nitroglycerine with inert material and forming it into cylindrical sticks. The point is to concentrate less of the dangerous material in each cell, thereby reducing the amount of that material likely to be involved in any catastrophe.

Also, the smaller cylindrical shape of the metal canister makes them much better at maintaining cell integrity under pressure... to the point that we now have cylindrical cells in production for portable computing devices and power tools that do not rupture under short-circuit, but rather bloat slightly and in many cases don't even vent gas before the internal fusible shunt opens up. Prismatic cells do not behave this way.

Cylindrical cells are simply safer because of this in a mobile application, wherein impact-induced puncture and crush damage are not only possible, they are inevitable.

We will see if Tesla's new larger cylindrical cells maintain this tendency; I do have my misgivings. But as they have said in the press releases, it's aboot finding the right balance between inherent safety, energy density, life of the super-pack, and being recyclable. 




Prismatic cells can make pack rebuilding a much less time-consuming affair, greatly increasing the likelihood it will be attempted as a service procedure rather than disposing of the entire super-pack. IMO this must be a core part of any EV ecology; it certainly does seem that Tesla's packs are made as hard to service as is humanly possible. I realize this is due as much to inherent difficulties of working with the cell type as with the exigencies of mass-production and the desire to make a high-performance pack vs a high-efficiency pack; but I do feel a lot more effort could have been made to facilitate rebuilding on a cell-by-cell level. That is a fukkin' lot of lithium power to treat even the individual sub-packs as a disposable unit.



As we can see here, the Prius super-pack is much more rebuild-friendly; however there is a lot less energy in this pack than the Tesla pack. Not sure exactly how energy density compares between the two by wet weight/volume tho.

EDIT: Just out of curiosity... did you work with the Prius Ni-MH technology or their Li-Ion tech, or both?

mnem
 

[bd139]

This is how to pack a delicate piece of TEA gear for shipment. These photos are of the outer carton, the actual packing  and the meter itself and its first power up, later I'll tear it down and snap some more pics, I;m excited, have never seen inside one of these before, and I'm wondering if has any similarities to the 4503 and the 1905A, one thing I can say is that when compared to the TTI counters and function generators, this 1906 is heavy, it as heavy as my HP3466A meter and that even has a SLA battery inside, so my fears of it wandering over the bench while being used were totally unfounded.

That’s a bloody miracle for CDL who shipped me a Tek 475 loose in a box. I’m impressed.

[Cubdriver]

At least only minimal Test gear was used. Kind of cool but wow on the $ even with the level of work eBay auction: #274391389907

It doesn't do anything for me, but the craftsmanship appears to be excellent.  And at least they used the Russian IN series nixies that are readily available, rather than pillaging an old piece of test gear for them...

-Pat

[mnementh]

Yeah, I think this is actually entirely one of those nixie clock kits from AliEx, only dressed up in a brass enclosure which has no rhyme or reason to its form. Shiny, but really a little too much useless crap/gewgaw/unicorn blarff lighting for my taste.

"glue gears on it and call it steampunk" indeed... 

mnem

[Cubdriver]

This is how to pack a delicate piece of TEA gear for shipment. These photos are of the outer carton, the actual packing  and the meter itself and its first power up, later I'll tear it down and snap some more pics, I;m excited, have never seen inside one of these before, and I'm wondering if has any similarities to the 4503 and the 1905A, one thing I can say is that when compared to the TTI counters and function generators, this 1906 is heavy, it as heavy as my HP3466A meter and that even has a SLA battery inside, so my fears of it wandering over the bench while being used were totally unfounded.

Are you suggesting that the individual who sent me this was remiss in their packaging?  (That is LITERALLY how it was packaged, and what I saw when I opened the box.)



Fortunately it is light weight and arrived in good nick.

-Pat

[Cerebus]

Same reason we pack dynamite into cylindrical sticks, and we consider a brick of C-4 in a box much more dangerous than an equivalent capacity of dynamite stored appropriately.

Erm, no we don't. Those of us who have held explosives licenses know that of two energetically equivalent quantities of C4 and dynamite, the dynamite is by far the more dangerous. I would cheerfully hit a slab of C4 with a hammer, I would happily set light to it with a match, in theory I would happily shoot it (there are limits to my faith in what I know in theory is true when it comes to high order explosions). I would most emphatically not do any of the same to a stick of dynamite unless I wanted to die.

[mnementh]

Yes... you know this and I do too. I'm talking aboot general perception, and actual potential for boom per package if actually set off. Agreed dynamite is much more dangerous to handle personally; particularly sweaty dynamite. One stick will kill you just as dead as a brick of C4; at which point you'll be far beyond concerns of collateral damage.

mnem
I prepared Explosive Runes today.

[mnementh]

Are you suggesting that the individual who sent me this was remiss in their packaging?  (That is LITERALLY how it was packaged, and what I saw when I opened the box.)



Fortunately it is light weight and arrived in good nick.

-Pat

"Packaged securely in eggcrate foam."

mnem

[Robert763]

There he go's posting  and changing it when called.
Also mainstream EV's don't use Li-po cells, you can't compare them.

[mnementh]

Dude... seriously. Now you're just being a ass.

 If you don't like what I have to say, please, for the love of all things that beep, chirp or blink... put me on ignore.

I am sick and tired of walking on eggshells for fear I'm going to offend your delicate technical sensibilities.

mnem

[Specmaster]

This is how to pack a delicate piece of TEA gear for shipment. These photos are of the outer carton, the actual packing  and the meter itself and its first power up, later I'll tear it down and snap some more pics, I;m excited, have never seen inside one of these before, and I'm wondering if has any similarities to the 4503 and the 1905A, one thing I can say is that when compared to the TTI counters and function generators, this 1906 is heavy, it as heavy as my HP3466A meter and that even has a SLA battery inside, so my fears of it wandering over the bench while being used were totally unfounded.

That’s a bloody miracle for CDL who shipped me a Tek 475 loose in a box. I’m impressed.

Maybe like me, they appreciate TTi gear more than most others  I have brought from them before and that packaging was almost identical.

[bd139]

I think they just hate me  .

How's the continuity on it? I understand it's shit but never actually tried it myself. Rest of the meter is good though 

[Cerebus]

I think they just hate me  .

How's the continuity on it? I understand it's shit but never actually tried it myself. Rest of the meter is good though 

Yeah, it's just you. 

I've had a fair bit off of CDL over the years, and the things that are most vulnerable to damage in transit, an Apple Cinema Display (Aluminium variety), an aluminium PowerMac (the big beasties), and a DL360, have all come in appropriate packaging and arrived in tip-top condition.

[bd139]

Impressive. I must have just hit a bad day.

I'd be scared of buying something like the cinema display based on the fragility and the propensity to end up with dead pixels off one of those.

[mnementh]

Same reason we pack dynamite into cylindrical sticks, and we consider a brick of C-4 in a box much more dangerous than an equivalent capacity of dynamite stored appropriately.

Erm, no we don't. Those of us who have held explosives licenses know that of two energetically equivalent quantities of C4 and dynamite, the dynamite is by far the more dangerous. I would cheerfully hit a slab of C4 with a hammer, I would happily set light to it with a match, in theory I would happily shoot it (there are limits to my faith in what I know in theory is true when it comes to high order explosions). I would most emphatically not do any of the same to a stick of dynamite unless I wanted to die.

   Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...

Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.

Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.

Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.

Does that comparison make more sense?


Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:

How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?

Nitroglycerine is still the same family of explosive, is it not?

mnem
 

[mnementh]

eBay auction: #293957155862

Wowzers... that little yellow Tek 222PS is now at $235 Canadian pesos with S/H, and still 4 days to go.   While it does still attract me viscerally, at that price I do find it quite resistible.

eBay auction: #293957158634

And the HeathKit IT-28 Cap Exploder () is  at $145 GWN legal tender with S/H, and also 4 days to go. 

Yeeeowwwch.

mnem
*time for walkies*

[Specmaster]

I think they just hate me  .

How's the continuity on it? I understand it's shit but never actually tried it myself. Rest of the meter is good though 

Continuity is just fine, superfast and reliable just a bit quiet. I think you'll find that it was the 1604 that had the shit continuity on it.

[Cerebus]

Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...

Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.

Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.

Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.

Does that comparison make more sense?


Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:

How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?

Nitroglycerine is still the same family of explosive, is it not?

mnem
 

Dynamite* is just nitroglycerin adsorbed or absorbed into some inert material to make it safer to handle - originally Kieselgur, a siliceous earth not unlike the Fuller's Earth we're all familiar with from cat litter. It's just a mixture, there's no change in chemistry; indeed the inertness of the ad/absorbent is necessary, historical versions have used wood meal to disastrous consequences as it's not strictly inert. The packaging is typically waxed paper, it facilitates handling and keeps water out and that's about it. Certainly the packaging into sticks offers no protection against explosion - if one stick detonated in a room every stick in the room would be detonated by that, even if yards apart. Nasty stuff and in the modern world it's obsolete as an explosive - there might be some edge use cases for it but if there are I don't know of them.

* There have been some bastard cousins going under the name of "Dynamite" such as 'military dynamite' which is basically RDX. But Dynamite per se gets all its explosive power from nitroglycerin.

[Specmaster]

Here are some more pics of the 1906, looks very impressive in its layout at first look until you look a bit deeper. There is a 3v Lithium 20mm button cell that retains the cal data and as this meter was made in 1997, I suspect that the cell needs replacing, and they stuck it in vertically, right beneath the IEC mains inlet and its boot. It looks like the whole backplate has to be removed, complete with the main's transformer and there a number of regulators hung from the backplate and directly soldered onto the main PCB. All of those mounting screws etc have to be removed in order to gain access to the battery 

No caps look to be bad infact it does not look like any gorillas have ever been inside this since it was made and the overall condition is only spoilt by a few scuffs on the top and a rubber foot missing, apart from that it could have been unboxed today, it's that good   

So apart from the battery location and that it needs a calibration (can do that myself with reasonable accuracy, certainly passable and agree with my other meters (all from the front panel as well) there is what appears to some discolouration / corrosion  on the leads of D12, shown just in front of those 3 resistors, in front of the battery, any ideas on what has caused the corrosion on these leads, there are zero signs anywhere else?

[bd139]

Looks pretty nice inside. As always with recent TTi. Got to love how they put their stuff together with generic parts always. No nasty ASICS with HP part numbers on them 

As for the cal data battery that definitely needs swapping out. Wonder if you can dump and restore the cal data

Edit: service manual covers all calibration options. Nice http://userequip.com/files/specs/1194/1906%20Service%20Manual%20(cct's%20incomplete%20+%20iss%20nos%20different).pdf

[PA0PBZ]

There is a 3v Lithium 20mm button cell that retains the cal data and as this meter was made in 1997, I suspect that the cell needs replacing, and they stuck it in vertically, right beneath the IEC mains inlet and its boot.

The battery terminals show some nice corrosion which makes me wonder if it is still alive.

[McBryce]

Same reason we pack dynamite into cylindrical sticks, and we consider a brick of C-4 in a box much more dangerous than an equivalent capacity of dynamite stored appropriately.

Erm, no we don't. Those of us who have held explosives licenses know that of two energetically equivalent quantities of C4 and dynamite, the dynamite is by far the more dangerous. I would cheerfully hit a slab of C4 with a hammer, I would happily set light to it with a match, in theory I would happily shoot it (there are limits to my faith in what I know in theory is true when it comes to high order explosions). I would most emphatically not do any of the same to a stick of dynamite unless I wanted to die.

   Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...

Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.

Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.

Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.

Does that comparison make more sense?


Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:

How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?

Nitroglycerine is still the same family of explosive, is it not?

mnem
 

Standard petrol (or gasoline to our cousins on the other side of the pool) has 31.5MJoules of energy per litre, that's 8.7kW/hrs in just one litre. Factors higher than the best battery on the market and we drive around with 40 to 50 litres of it in a glorified bucket every day. If safety didin't bother us up to now, why should it now?

McBryce.

[mnementh]

   Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...

Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.

Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.

Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.

Does that comparison make more sense?


Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:

How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?

Nitroglycerine is still the same family of explosive, is it not?

mnem
 

Standard petrol (or gasoline to our cousins on the other side of the pool) has 31.5MJoules of energy per litre, that's 8.7kW/hrs in just one litre. Factors higher than the best battery on the market and we drive around with 40 to 50 litres of it in a glorified bucket every day. If safety didin't bother us up to now, why should it now?

McBryce.

You're fucking kidding, right?

I'm scared shitless of the stuff. 

I used to work in a boneyard cutting cars up with torches. I've had more than a few near-misses and regrown eyebrows. And been literally blowed-up by a propane furnace. As in blasted across the basement, with 3rd degree burns from wrist to armpit. And then there were the gasoline-mist and BLEVE demonstrations which were part of my volunteer firefigher basic training.

mnem

[mnementh]

Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...

Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.

Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.

Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.

Does that comparison make more sense?


Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:

How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?

Nitroglycerine is still the same family of explosive, is it not?

mnem
 

Dynamite* is just nitroglycerin adsorbed or absorbed into some inert material to make it safer to handle - originally Kieselgur, a siliceous earth not unlike the Fuller's Earth we're all familiar with from cat litter. It's just a mixture, there's no change in chemistry; indeed the inertness of the ad/absorbent is necessary, historical versions have used wood meal to disastrous consequences as it's not strictly inert. The packaging is typically waxed paper, it facilitates handling and keeps water out and that's about it. Certainly the packaging into sticks offers no protection against explosion - if one stick detonated in a room every stick in the room would be detonated by that, even if yards apart. Nasty stuff and in the modern world it's obsolete as an explosive - there might be some edge use cases for it but if there are I don't know of them.

* There have been some bastard cousins going under the name of "Dynamite" such as 'military dynamite' which is basically RDX. But Dynamite per se gets all its explosive power from nitroglycerin.

Okay... then that makes this analogy relevant as far as dilution, but not as far as the armor casing we use on battery cells.* Understood dynamite is only relatively "safer" than liquid nitroglycerine. Thanks for the lesson aboot the nature of the inert material.

Is there more to it than simple dilution with better inert materials with C-4? I understand the stuff "burns" slower, which makes it possible to use it for a cutting action; but I've deliberately avoided further study due to a parallel incident (not involving myself in any way) involving class C fireworks which caused a come-to-Jesus dialog with myself many years ago when I was just getting into it.


*Indeed, such a metal shell is how naughty people make pipe-bombs. Li-Ion cylindrical cells have been deliberately evolved over decades to include sufficient gas expansion volume and fuse-shunts and better mechanical sealing such that short-circuit-induced rupture in most cases is very infrequent, and first vented by a gas seal diaphgragm.

mnem