a (mostly) invisible difference between my civilian & military Fluke gear

[arcitech]

I realize correlation is not causation, but the only thing that differentiates the center rubber holster from that on the left, and the yellow polymer on the right, is that those two came from the US military. The center holster did not (meter did, original USAF holster is on the left).

Curiously, the person selling a few dozen holsters (I picked up a few) disclosed that they were new and their (meter) customer didn’t want the holsters. I didn’t think much of it at the time, but after flipping up the phosphor disc on a (near-UV?) dive light I’ve got (for making underseascapes a bit of a trip), I noticed this. Searched around a bit, couldn’t find any info. Figured I’d share and maybe ask others with blueshifted wavelengths and a few Flukes in the collection to check and see if they notice anything interesting…

[robert.rozee]

it may well be that part of the military acquisition specs that NOTHING fluoresces under UV light. imagine the other side being able to use UV lights to make soldiers in the battlefield light up!

it is probably listed under under the rule, "we do NOT make battleships out of aluminium (or aluminum)"   


cheers,
rob   :-) 

[AlfBaz]

it may well be that part of the military acquisition specs that NOTHING fluoresces under UV light. imagine the other side being able to use UV lights to make soldiers in the battlefield light up!

it is probably listed under under the rule, "we do NOT make battleships out of aluminium (or aluminum)"   


cheers,
rob   :-)

If memory serves from my time at Garden Island, the top half of ships like the HMAS Sydney, Darwin etc where made out of an aluminium alloy that was intended to burn up at very high temperatures to incinerate all the top secret gear they had in there...
Then again it could of been a myth, I was only there for a couple of months
 

[Fungus]

If memory serves from my time at Garden Island, the top half of ships like the HMAS Sydney, Darwin etc where made out of an aluminium alloy that was intended to burn up at very high temperatures to incinerate all the top secret gear they had in there...
Then again it could of been a myth, I was only there for a couple of months

I doubt they'd make battleships that could be destroyed by a single 50-cal incendiary round.

[Wrenches of Death]

it is probably listed under under the rule, "we do NOT make battleships out of aluminium (or aluminum)"   

I had a job in the 1970's removing electronic gear from a couple of USN ships being scrapped. I worked on two cruisers, the Topeka and the Boston. I remember a lot of bulkheads above the main deck as being thick aluminum. Maybe an inch and a half or two inches thick. Oh, add another 1/4 inch for the layers of lead paint. I can still remember the smell of it when cutting bolts and brackets.

WoD

[Fungus]

it may well be that part of the military acquisition specs that NOTHING fluoresces under UV light.

Very plausible.

I've got some army pants with a warning against washing with ordinary detergent to avoid that problem.


(most washing powders have fluorescent stuff in them to make your sheets look whiter in sunlight)

[Fungus]

Pretty much all of the bulkheads above the main deck I remember as being thick aluminum. Maybe an inch and a half or two inches thick. Oh, add another 1/4 inch for the layers of lead paint.

Why would they add 1/4 inch of heavy paint to aluminum?

[Wrenches of Death]

Why would they add 1/4 inch of heavy paint to aluminum?

Everything had been painted dozens and dozens of times over the decades. There were areas where sheets of paint were peeling off. The layers looked like rings of a tree. It wasn't all a quarter of an inch thick, but there were areas that were. Distinct smell too, even when it wasn't burning.

WoD

[Fungus]

Why would they add 1/4 inch of heavy paint to aluminum?

Everything had been painted dozens and dozens of times over the decades.

I wouldn't have thought that aluminum needed any painting. It doesn't rust and it already comes in battleship grey color.

Still: There's the right way, the wrong way, and the military way...

[arcitech]

One memorable lesson I learned working in aerospace was around alumin(i)um oxidation -- it is certainly worth caring about in a variety of mission critical scenarios, such as those involving various altitude/temperature extremes, and likely also high salinity environments. Sure, it doesn't "rust" in the commonfolk sense of the term, but the mechE cautioning me as I cut holes into a vehicle of my own as I installed some electronics gear made it very clear to me (and I trusted him enough to feel like I didn't need to fact check): Al does in fact rust. It may not look like the popular definition of rust, and it may not spread like that sort of rust either, but apparently it's enough of a concern that, for some applications, any opportunity for (ongoing, not immediate) oxidation of Al warrants countermeasures.

[sokoloff]

Why would they add 1/4 inch of heavy paint to aluminum?

Everything had been painted dozens and dozens of times over the decades.

I wouldn't have thought that aluminum needed any painting. It doesn't rust and it already comes in battleship grey color.

Still: There's the right way, the wrong way, and the military way...

Exactly. There's a happy overlap in mission between "these things need painting in order to protect them" and "these enlisted painters need things to paint in order to keep them busy".

[tooki]

One memorable lesson I learned working in aerospace was around alumin(i)um oxidation -- it is certainly worth caring about in a variety of mission critical scenarios, such as those involving various altitude/temperature extremes, and likely also high salinity environments. Sure, it doesn't "rust" in the commonfolk sense of the term, but the mechE cautioning me as I cut holes into a vehicle of my own as I installed some electronics gear made it very clear to me (and I trusted him enough to feel like I didn't need to fact check): Al does in fact rust. It may not look like the popular definition of rust, and it may not spread like that sort of rust either, but apparently it's enough of a concern that, for some applications, any opportunity for (ongoing, not immediate) oxidation of Al warrants countermeasures.

Well… no. Rust specifically and exclusively means iron oxide, and only iron can oxidize to iron oxide. But aluminum does oxidize. (In other words: rusting is not a synonym for oxidation, it’s a very specific oxidation.)

[james_s]

As I recall, aluminum oxidizes more readily than iron. The difference is that aluminum oxide mostly stays on and provides a protective coating.

[jfiresto]

... I wouldn't have thought that aluminum needed any painting. It doesn't rust and it already comes in battleship grey color....

It depends on the alloy. The original Duralumin (series 2000) aluminum used by Count Ferdinand von Zeppelin, for example, contains copper, and often needs an outer cladding to protect it against corrosion.

Attached is some aluminum 2014 that has been turning brown just sitting on the shelf.

[tooki]

As I recall, aluminum oxidizes more readily than iron. The difference is that aluminum oxide mostly stays on and provides a protective coating.

Yep. It passivates precisely because it’s so reactive. The oxide is hard, and above all isn’t larger than the metal it consumed. (That’s the problem with rusting: rust is physically larger than the iron, so it necessarily starts flaking off, exposing more bare metal…)

[arcitech]

One memorable lesson I learned working in aerospace was around alumin(i)um oxidation -- it is certainly worth caring about in a variety of mission critical scenarios, such as those involving various altitude/temperature extremes, and likely also high salinity environments. Sure, it doesn't "rust" in the commonfolk sense of the term, but the mechE cautioning me as I cut holes into a vehicle of my own as I installed some electronics gear made it very clear to me (and I trusted him enough to feel like I didn't need to fact check): Al does in fact rust. It may not look like the popular definition of rust, and it may not spread like that sort of rust either, but apparently it's enough of a concern that, for some applications, any opportunity for (ongoing, not immediate) oxidation of Al warrants countermeasures.

Well… no. Rust specifically and exclusively means iron oxide, and only iron can oxidize to iron oxide. But aluminum does oxidize. (In other words: rusting is not a synonym for oxidation, it’s a very specific oxidation.)

Thanks for rectifying what the better part of a decade has degraded.

An edit taking that correction into account, not up there, but just right here:
Al does in fact [oxidize]. It may not look like the [actual] definition of rust, and it may not spread like [actual] rust either, but apparently it's enough of a concern that, for some applications, any opportunity for (ongoing, not immediate) oxidation of Al warrants countermeasures.

I wonder then whether at sea this was in fact busy work, or warranted.

—

Chances are slim I guess of anyone sharing findings, let alone photos, of actual meters, but fingers are still crossed…

[daisizhou]

Your FLUKE 27 looks like a civilian version, the military one should be 27/FM, and it's brown

[CatalinaWOW]

arcitech has nailed it.  In the applications where most people encounter aluminum it is very corrosion resistant.  I have aluminum siding on some of my shops that is more than 40 years old, unpainted and looks like new.  But I live in a cool inland environment.  Negligible salt and whenever it is hot it is very dry.  I have been at beachside in hot environments where you can almost watch the progression of rust in ferrous materials and even aluminum frequently shows degradation over intervals much shorter than a decade.

Add to that the problems caused by dis-similar metals in contact with salty water and there is a definite need to protect even aluminum.  Warships are expensive and nations which operate them try to get many decades of service out of them.  Things that would not cause problems in a consumer product that is usually taken out of service in a decade or two are real issues for these machines.  The designers try to avoid contact between metals with different voltaic potential, but it is impossible to achieve this everywhere, so a moisture barrier paint is a good choice.

A quarter inch of paint may have been a bit of an exaggeration, but the number of 10 mil layers that can be applied in a 50 year service life is impressive.  Even when you think about the fact that chipping or scaling is part of the painting drill that keeps idle sailors hands out of trouble.

[arcitech]

Your FLUKE 27 looks like a civilian version, the military one should be 27/FM, and it's brown

The old ones are gray. The newer ones were not. The FM is indicated on the label affixed to the rear, and it came in a standard mil case of that vintage with the RF and HV probes.

Or I’m just wrong.

[daisizhou]

I've been using this model as well, the point is that the military internals are RMS voltages and civilians are average.

[bdunham7]

I've been using this model as well, the point is that the military internals are RMS voltages and civilians are average.

Not so simple.  The ones that say 'Fluke 27' are average-responding and the ones that say 'Fluke 27/FM' on the front are RMS-responding.  The appearance of 'FM' or any other letters on the back sticker have no bearing on the issue.  There are many other sub-variations as well, but I believe that at some point Fluke stopped selling them to all but military customers and those later ones were not RMS responding types.  The one I have is non-RMS-responding, CAT-III with the grey face, USMC new surplus and manufactured in 2006.  I have not seen any newer than that. 

[arcitech]

I've been using this model as well, the point is that the military internals are RMS voltages and civilians are average.

Not so simple.  The ones that say 'Fluke 27' are average-responding and the ones that say 'Fluke 27/FM' on the front are RMS-responding.  The appearance of 'FM' or any other letters on the back sticker have no bearing on the issue.  There are many other sub-variations as well, but I believe that at some point Fluke stopped selling them to all but military customers and those later ones were not RMS responding types.  The one I have is non-RMS-responding, CAT-III with the grey face, USMC new surplus and manufactured in 2006.  I have not seen any newer than that.

This is correct. The latest 27/FM variants, both colored like yours and like mine, are more in line with the 27II in that they’re average responding, which is presumably why the copy along the display bezel lacks the /FM designation, likely for differentiation at a glance.

[arcitech]

I've been using this model as well, the point is that the military internals are RMS voltages and civilians are average.

I thought the point was that mine looks like a civilian variant, which it does. So on that point, which it seems was not at all the point, you’d be correct. I don’t mean to sound like an asshat, but I suppose I do.

[srb1954]

Your FLUKE 27 looks like a civilian version, the military one should be 27/FM, and it's brown

The old ones are gray. The newer ones were not. The FM is indicated on the label affixed to the rear, and it came in a standard mil case of that vintage with the RF and HV probes.

Or I’m just wrong.

My 27/FM is labelled as "FLUKE 27/FM Multimeter" in the space above the display.

There is another label on the back with a whole lot of military part numbers and so on but no indication of the actual Fluke model number.

[arcitech]

I suppose I now have a reason to find a decomm’d Agilent/Keysight handheld, and a civilian model to compare with. I’d guess that’s one way to see if this is consistent across brands.

The twinkle in my eye for the HP/Agilent gear really has vanished ever since [wow that list got super long so it’s below the fold if you’re curious]. I sort of gag at the notion of spending money on their stuff now, even on the second-hand market.

—

they decided to refuse my (domestic) business access to the parts store simply because its website is about as minimally present as is possible (rather common in security — an industry they claim to serve but clearly don’t grok either the industry nor the concept of the word), and for some reason continue to do so despite being pointed to the gov site that verifies my business; they terribly botched a GDPR request that somehow subscribed me to more spam that read “Hi GDPR,”; they  never cared about let alone remedied my access to loads of (seemingly their own?) assets in the asset management console, then at one point spammed me about having it all — the gear that I’ve got nought to do with — calibrated. That garnered an email letting them know once again about how none of these things are mine, to web support. And somehow support interpreted that as an indication that they should have someone in the service department email me a quote to have all the gear that’s not mine calibrated.

My lab was built around a Keithley, four HPAK meters and four HPAK power supplies earlier this year, and this whole ordeal has resulted in a pair of 8846As, another two 8842As, and an HMP4040 making their way into the lab so I don’t get bummed when using the HPAK kit and wishing the company could just manage to have a quarter the integrity and substance it used to, because I’m a delicate fucking flower who sobs over these things, especially having been born a bit too late after everything — not just this one faceless corporation — has apparently turned to shit.

A cheery morning indeed lol.