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Whats the most unique engineering unit you've encountered?
3

Whats the most unique engineering unit you've encountered?

Whats the most unique engineering unit you've encountered?

(OP)
For fun, what is the most unique engineering unit you've encountered in your years?

Some considerations:
  • Name
  • Units that mixing and matching english and metric
  • Usefulness & practicality
My two first nominations:
  • KW/foot: A mix & match of english & metric, its used in the commercial nuclear power industry. The unit is a of measure of the amount of energy produced in metric, per linear foot of fuel rod. The calculation is important for evaluating the heat transfer capacity to the water in the reactor. Too much energy will result in fuel clad damage, compromising the integrity of the first fission barrier
  • slinch: The slinch is an english unit of mass equal to 1 lbf*sec^2/in. (Think Weight divided by 386.6in/sec^2) In my opinion it has almost no practical application except for use in the mass input for english-unit based Finite Element Models.
Excited to hear your nominees

Jeff
Pipe Stress Analysis
Finite Element Analysis

www.xceed-eng.com

RE: Whats the most unique engineering unit you've encountered?

I did some work about 50 years ago, on teeth, and the measurements were in microns, and the data had to be reviewed statistically to determine if it was from the same 'family'. Unique enough?

RE: Whats the most unique engineering unit you've encountered?

I don't think I have anything quite that colorful.

My AP physics teacher (1975-ish) was very fond of furlongs per fortnight. Much to my delight, Mathcad 15 has both furlong and fortnight as built-in units, so it's 166.3095 microns/second

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
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RE: Whats the most unique engineering unit you've encountered?

While I never found an actual engineering use for it, when I used to do CAD demos and people would ask what sort of units were supported when creating parametric formulas, my favorite example would include something that involved a Velocity valued in 'Furlongs/Fortnight' winky smile

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Whats the most unique engineering unit you've encountered?

6.548x10^(-3) in/sec... interesting... I had no idea it was so small...

Smoot is good... approx 1.7018 m... cubit, anyone?

Dik

RE: Whats the most unique engineering unit you've encountered?

My brother the programmer mentioned once that he uses some rather interesting and unusual units at times as one simple method to protect his work from corporate thievery, I never knew until then the origin of the Google name in googol.

RE: Whats the most unique engineering unit you've encountered?

A (Carl) Sagan is defined as a unit of measurement equivalent to a very large number of anything. I first saw it in the editorial section of an astronomy zine that was talking about the number of stars in the observable Universe. Have yet to use it, but I think I can use it in conjunction with Avogadro's number if I ever wanted to give a tech reviewer a hard time tongue

RE: Whats the most unique engineering unit you've encountered?

CWB1 No wonder we missed mars.

Jar, a Sagan is billions of billions of anything.

Has anyone used the term Kilo dollars, drives the book keepers nuts.

RE: Whats the most unique engineering unit you've encountered?

That and kilobucks and megabucks...

Dik

RE: Whats the most unique engineering unit you've encountered?

While I never had the nerve to hand in an assignment with this on it, I used to confuse my classmates while doing homework problems together by writing the units of bending moment as:
Newton-kilometers

Their reaction to this unit turned out to be an accurate way to predict their final grade in Statics and Mechanics of Materials classes.

STF

RE: Whats the most unique engineering unit you've encountered?

Quote (Cranky108)

Jar, a Sagan is billions of.....

I had to read that two or three times before I realised you were addressing a person called Jar, rather than nominating the Jar (=1111 picofarads) as an incongruous unit.

A.

RE: Whats the most unique engineering unit you've encountered?

JGard1985,

An old colleague of mine tried to introduce the term SNAK. A SNAK was two bytes of data, as opposed to the Word, which is dependent on architecture.

It did not catch on, as you may have noticed.

--
JHG

RE: Whats the most unique engineering unit you've encountered?

An unusual one: "Grace Hopper Nanosecond"
A unit that combines length with time. When early computer authority Grace Hopper began a talk she would pass out pieces of wire about one foot long... the distance electricity will travel in one nanosecond (1 x 10-9 seconds).

Useful: "Acre-Foot"
A unit of volume. An area of one acre that is one foot deep. (43,560 cubic feet). Often used as a measurement of the volume of a body of water, such as a detention pond.

www.SlideRuleEra.net idea
www.VacuumTubeEra.net r2d2

RE: Whats the most unique engineering unit you've encountered?

Used to use acre-foot for pondage for hydro electric development and size of reservoir and height of dam calculations.

Dik

RE: Whats the most unique engineering unit you've encountered?

From work in quantum physics of nearly 50 years ago... a Barn = 10^(-24) cm^2

from wiki,
"...secretive unit to describe the approximate cross sectional area presented by the typical nucleus (10−28 m2) and decided on "barn." This was particularly applicable because they considered this a large target for particle accelerators that needed to have direct strikes on nuclei and the American idiom "couldn't hit the broad side of a barn."

RE: Whats the most unique engineering unit you've encountered?

With respect to the so-called "Grace Hopper Nanosecond", there's more to the story. In addition to the individual pieces of wire, each representing the distance that an electron travels in a nanosecond, that she handed out to the people attending her seminars, she also had in her own hand a large coil of wire which represented the distance that an electron traveled in a millisecond. She used these two example lengths of wire to make the point that when programming a computer, being willing to accept an operation that took a millisecond versus working harder to get something to compute in only a few nanoseconds makes a really big difference.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Whats the most unique engineering unit you've encountered?

Not sure if it is an engineering unit, but "blibbit" comes to mind when reading this thread.

RE: Whats the most unique engineering unit you've encountered?

John Baker,
At one time I had a VHS video tape of Grace Hopper doing that lecture , handing out the pieces of wire and explaining their significance. She also had iddy bitty pieces of wire for higher frequencies.
B.E.

You are judged not by what you know, but by what you can do.

RE: Whats the most unique engineering unit you've encountered?

Here's a segment of that Grace Hopper 'Nanosecond' lecture:

https://www.youtube.com/watch?v=JEpsKnWZrJ8

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Whats the most unique engineering unit you've encountered?

Horsepower:

Mechanical
Metric
French and Italian Tax
Electrical
Hydraulic
Boiler
Drawbar
RAC
Nominal
Indicated
Brake
Shaft
Wheel
SAE
SAE gross
SAE net
SAE certified
DIN 70020
CUNA
EEC
ISO
JIS D 1001
And it doesn't stop here.

Sourse: Wikipedia

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: Whats the most unique engineering unit you've encountered?

My father saw one of those Hopper lectures. Later, he sent me a copy of the article along with this yellow piece of wire (coax, actually). Not knowing the significance, I tossed the wire thinking it was simply him getting old and including random crap. It was years later that I figured it out, and I regret tossing that cable.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: Whats the most unique engineering unit you've encountered?

Cow's grass - the amount of land that can support a single cow
Hobo Power - a measure of stink from the radio show Loveline. Negative Hobo Power can cancel out positive Hobo Power.

RE: Whats the most unique engineering unit you've encountered?

Reporting gas volumes is a major thing in Oil & Gas. I taught a class once in London with students from 8 countries. I asked "I know none of you are happy with standard cubic feet being used, but what do you use instead?" The answers were interesting:
  • e3m3 (103 cubic meters) was used by some
  • (km)3 was reported by several
  • SCM
  • Nm3
  • NCM
  • GJ
I asked the class their definition of "standard" and "normal" and got into a muddle. The Australian approach of assuming that the gas is 948 BTU/SCF so 1 MSCF = 1 GJ was especially creative.

The Oil & Gas approach to use the "M" prefix for 1000 (the Roman Numeral "M"), and then instead of the Roman approach of MM being 2,000 it becomes 1,000,000 has always fascinated me.

I used to be involved in downhole tubular goods and it was very common to specify "600 m of 2-3/8 inch tubing".

I also like the UK speed limit signs in km/h with distance signage in miles (or is it vice versa, it has been a while).

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

RE: Whats the most unique engineering unit you've encountered?

erg and slug

Dik

RE: Whats the most unique engineering unit you've encountered?

Blibbit: ten pounds of faeces in a five-pound bag. Origin: U.S. rural. Refers to anything filled to or beyond capacity.

Dik

RE: Whats the most unique engineering unit you've encountered?

David, you got it right the first time: "I also like the UK speed limit signs in km/h with distance signage in miles..."

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Whats the most unique engineering unit you've encountered?

Traditional units of length in Japan, still used for carpentry and agriculture.

https://en.wikipedia.org/wiki/Japanese_units_of_me...

Quite common to see tape measures with the "sun" as the primary division and also meters.

RE: Whats the most unique engineering unit you've encountered?

We added a units conversion to a program that prints calibrated flow test data tags, which is always a pain the a$$ when you consider sig. figs and rounding. But the customer wants what the customer wants...

So the programmer and I agreed to add our own units conversion - kBLqf, which is the abbreviation for kilo-buttloads per fortnight. Useful little unit, turns out to be about 6-1/4 gallons per minute.

RE: Whats the most unique engineering unit you've encountered?

dik, known as a "blivet" around here...

I used to volunteer at a local festival. When building the dance floors we lay 2x6's flat and deck 'em with plywood. I'd explain to the crews we would space the 2x6's on 16 inch centers. I'd show them the 16 inch marks on a tape measure and say, "Now these tapes are marked so that even carpenters can find 16 inch centers."

So, I dunno, 16 inch equals one Stud? or two Studs?

The problem with sloppy work is that the supply FAR EXCEEDS the demand

RE: Whats the most unique engineering unit you've encountered?

Where I came from, a "blivet" was defined as "10# of 'excrement' in a 5# bag".

That being said, the word "blivet" actually does have a definition out on the web:

https://en.wiktionary.org/wiki/blivet

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Whats the most unique engineering unit you've encountered?

Quote (zdas04)

I also like the UK speed limit signs in km/h with distance signage in miles (or is it vice versa, it has been a while).

That's odd - I'd like to think that if it was like that, I'd have noticed by now.

Speed limits are posted in (statute) miles per hour and distances to destinations and junctions are in (statute) miles. The only place I see km in regular use is on the small Driver Location Signs and associated Distance Marker Posts on the side of major roads (that nobody ever looks at unless they've broken down and need to explain to somebody where they are).

A.

RE: Whats the most unique engineering unit you've encountered?

Quote (SnTMan)

So, I dunno, 16 inch equals one Stud? or two Studs?
Unless you're in an area where a stud separation is 24"... noevil

Dan - Owner
http://www.Hi-TecDesigns.com

RE: Whats the most unique engineering unit you've encountered?

would 'sack of hammers' qualify as a unit?

Dik

RE: Whats the most unique engineering unit you've encountered?

MacGyver... you're talking about 'stud and a half' country...

Dik

RE: Whats the most unique engineering unit you've encountered?

how about a unit called 'the Donald'. A new unit, to suit, anything every day...

Dik

RE: Whats the most unique engineering unit you've encountered?

I wisht my garage ceiling joists were spaced at Stud or Stud-and-a-half when I was flooring it. They were spaced at approximately Stud-and-a-half. Some were 25 inch, some were 27 inch, no two exactly alike. It took a very detailed cut list to make it work with common lumber lengths :)

The problem with sloppy work is that the supply FAR EXCEEDS the demand

RE: Whats the most unique engineering unit you've encountered?

Although they are very prevalent terms, I always thought a "chord" and "board feet" were unusual terms for units of wood.

Also.....a pony keg, in reference to a partial (1/2 or 1/4??) keg of beer

RE: Whats the most unique engineering unit you've encountered?

Quote (dik)


would 'sack of hammers' qualify as a unit?

I have heard the term "dumb as a sack of hammers". I have not heard the term "dumb as 21.7 sacks of hammers".

--
JHG

RE: Whats the most unique engineering unit you've encountered?

MotorCity,

As to wood, especially firewood, it is "cord", not "chord".

RE: Whats the most unique engineering unit you've encountered?

drawoh... that's 21.7 times as dumb...

Dik

RE: Whats the most unique engineering unit you've encountered?

Hokie:

and either a Face Cord or a Bush Cord, or a Logger's Cord?

Dik

RE: Whats the most unique engineering unit you've encountered?

zeusfaber:

jar from Leyden Jar perhaps?

Dik

RE: Whats the most unique engineering unit you've encountered?

drawoh:

I remember approaching the Mayor of the Town of Lindsay (now, City of Kawartha Lakes) about 20 years ago and asking him if I could get a sack and have Home Hardware there donate a bunch of hammers and if we could have a 'Sack of Hammers' award for the most deserving Councilman... he was not pleased...

Dik

RE: Whats the most unique engineering unit you've encountered?

Many of you probably know, but an acre is 10 square chains, a chain being 66 ft in length, and there are 100 links in a chain. Probably an early acknowledgment that 10 is a simpler number to work with than 12.

Another interesting area unit is the perch. 40 perches = 1/4 acre, a common size housing block in a lot of countries.

RE: Whats the most unique engineering unit you've encountered?

Barrel of monkeys? monkey

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: Whats the most unique engineering unit you've encountered?

Here is a detailed explaination of the chains roods perches system.

B.E.

http://rootsweb.ancestry.com/~engwahs/area.htm

You are judged not by what you know, but by what you can do.

RE: Whats the most unique engineering unit you've encountered?

Quote (dik)

jar from Leyden Jar perhaps?

I think so. So far as I know, they used to tune the early shipborne wireless sets by wiring additional leyden jars into circuit (increasing the capacitance by a jar or two at a time).

A.

RE: Whats the most unique engineering unit you've encountered?

zeusfaber... didn't know that, thanks. Other than a novelty, I didn't think Leyden Jars had a real use.

Dik

RE: Whats the most unique engineering unit you've encountered?

Zeusfaber,
I found a reference to that in my dad's Hand book of wireless telegraphy.
It basically said," The Jar is now obsolete as the service unit, having been replaced by the Farad and its sub multiples."
It never said whether or not that was a direct substitution.
B.E.

You are judged not by what you know, but by what you can do.

RE: Whats the most unique engineering unit you've encountered?

From Wikipedia:
A jar was an early unit of capacitance once used by the British Royal Navy. The term originated as the capacitance of a Leyden jar. Its value is such that one farad is9×108 jars and one jar is 1111 picofarads.

RE: Whats the most unique engineering unit you've encountered?

berkshire:

I didn't know that Leyden Jars were used outside of school physics labs... if they are around, they could be historic collectables. I've got an old Roentgen tube from decades back and a couple of chunks of cable samples, the latter from a project. My only electrical part collection.


RE: Whats the most unique engineering unit you've encountered?

DIK,
Is that old under sea cable?
B.E.

You are judged not by what you know, but by what you can do.

RE: Whats the most unique engineering unit you've encountered?

It's for direct buried; I don't know if it can be submerged other than some groundwater. The project had 4 runs of it (one spare) x 4 kilometers @ $75 per foot going to 6 - 400,000 lb transformers... Oil containment for each was 1-1/2 rail tanker cars. The one electrical engineer brought back a 'sackful' of samples and I managed to scrounge a couple. Prior to that, my largest conductor size was half the diameter and I thought that was huge.

It's new material.. outer poly sheath, spiral wound copper grounding 'cage', a semi-conductor, insulation, a semi-conductor and the copper conductor.

Dik

RE: Whats the most unique engineering unit you've encountered?

Not an engineering unit but I have had the good fortune to use the term "in the event of catastrophic milkshake failure" during a project presentation.

RE: Whats the most unique engineering unit you've encountered?

Berk and JG,
And that is why my front property stakes are actually 66' from the center of the street.
I have had to explain that to a number of people over the years.
In the mid-west most roads have 122' RoW, it was just easier that way.

In metallurgy we don't have many invented units, just use whatever is handy.
Until recently when paper editors got mean about it you would see a paper with strength in ksi, grain size in microns, atomic spacing in angstroms, and density in g/cc. Since you weren't doing math between units it didn't really matter.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Whats the most unique engineering unit you've encountered?

A traditional unit for measuring fields in Greece, before WWII, was called "zevgaria" meaning "pair of", and as you can imagine it means the area that a pair of oxen or horses can plow in a day. It was equal to anything between 2000 and 4000 m2, with most usual 2500 m2.

The Dictionary of Units of Measurement has plenty of information for other strange uom.

RE: Whats the most unique engineering unit you've encountered?

CostasV,

In Saxon England, fields were measured in hides. I believe this was the field an ox could plough in one day.

--
JHG

RE: Whats the most unique engineering unit you've encountered?

<peeve>
The common unit for liquid flow resistance, Cv, is often stated as if it were dimensionless.
It is not.
Its units are:

gpm/square root(psid)

The square root function is often omitted in textbook definitions, and is misleading as commonly stated because 1 is its own square root, so it takes a while to figure out how to compute a Cv from a given pressure drop other than 1 psi and a corresponding flow.

</peeve>

Engine manufacturers who work in metric units will often supply Cv's metric inverse equivalent (less scaling constants):

mbar/(m^3/h)^2

for use in pressure drop calculations.
I don't know of a convenient name, but it is occasionally useful, if uncommon here in The Colonies.
I think I have seen it labeled as K or maybe F.


In my spreadsheets, I use
K=68.9476/0.05159/Cv^2
to convert from one to another.





Mike Halloran
Pembroke Pines, FL, USA

RE: Whats the most unique engineering unit you've encountered?

I recall many, many years ago when we were given pressure in the units of Torr. There was no internet back then, so it took us quite a while to figure out that a Torr was (supposed to be) a millimeter of mercury.

--
JHG

RE: Whats the most unique engineering unit you've encountered?

Figanewtons and Boxafiganewtons, from my Holtz and Kovacs Geotechnical Engineering textbook (see attached file). Never encountered it the real world, but it must exist because it's in a textbook.

And I once had a young engineer give me a quantity in "Gallons of Bridge Rail."

RE: Whats the most unique engineering unit you've encountered?

And people say engineers have no sense of humor...

The problem with sloppy work is that the supply FAR EXCEEDS the demand

RE: Whats the most unique engineering unit you've encountered?

How about a 'Bucket of Shims'?

I just remembered that when I still worked in 'hard engineering' (before I changed careers and moved to software in 1980) we manufactured large pieces of machinery for commercial bakeries. These machines were shipped in pieces and erected (assembled) on-site. Since most of the framework was fabricated from welded structural shapes and set-up on existing concrete floors, we provided what we called a 'U-shim', a square piece of stainless steel in various thicknesses with an open-ended slot/notch on one side of the shim so that they could be installed between mated parts without having to completely remove the bolts by simply loosening the fasteners and sliding in as many shims as needed to square-up a frame or assure proper alignment with the next piece of equipment. These were made in various thicknesses from scrap pieces in the sheet-metal shop (we had a small press set-up all the time to make these, when guys had nothing else to do and there was scrape laying around) and they were packaged in sturdy plastic buckets, each holding approximately 25 lbs of shims and that's how they went into inventory. So for each machine shipped there would be an item on the Bill of Material for a 'Bucket of Shims'. It had a part number and even a 'drawing', a size 'A' sheet with the words "ONE BUCKET OF SHIMS" written on the face of the drawing and a parts list to account for the plastic bucket and 25 lbs of stainless steel.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Whats the most unique engineering unit you've encountered?

"Eaches" as in "Each item shipped separately"

Sold in eaches.

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: Whats the most unique engineering unit you've encountered?

Not a unit, but I did a carved balsa sign support in Lindsay for the theatre and at the first meeting, where the contractor, the architect and myself were present, the contractor commented that the documents were great but he had a question... He asked, "what's a thingamajig." I asked why and he said it was spec'd on the drawing, and sure enough it was there.

When the draftsman was preparing the drawings, he asked what this thing was that a cable looped around to distribute the load and keep from crushing the cable... I didn't know at the time, so, replied that it was some sort of thingamajig... and he put it on the documents. I thought it was really funny, but, the Architect went ballistic, for no real reason. I later found out it was called a thimble.

Dik

RE: Whats the most unique engineering unit you've encountered?

Dik,
It was a thimble eh, and you did not sew with it ?
B.E.

You are judged not by what you know, but by what you can do.

RE: Whats the most unique engineering unit you've encountered?

berkshire... it bothered me a bit that the Architect went ballistic, his reaction was a reflection of work prepared on his drawing titles... I could only sit back...

Dik

RE: Whats the most unique engineering unit you've encountered?

Back when I took 3rd semester physics in college (1977), a buddy and I worked through converting furlongs per fortnight to parsecs per picosecond, rather than listen to the prof drone on about something that was probably important. smile

Now Google can tell me that 1.00 furlong per fortnight equals 5.38974 x 10^-33 parsecs per picosecond. And, of course, the inverse is 1.00 parsecs per picosecond equals 1.855 x 10^32 furlongs per fortnight.

==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

RE: Whats the most unique engineering unit you've encountered?

The only odd unit that I'm familiar with is machine shop terminology for "a wee little bit".

Unfortunately, the name of that unit is probably not family friendly although I'm sure other people with shop backgrounds know exactly what unit I'm talking about ... Can we say it here? Ain't gonna be me ...

RE: Whats the most unique engineering unit you've encountered?

Could this be the one that Humph Lyttleton used to bowdlerize as "a gnat's crotchet"?

A.

RE: Whats the most unique engineering unit you've encountered?

In Winnipeg, due to the condition of our roads... we have potholes/kilometer. Does that count?

Dik

RE: Whats the most unique engineering unit you've encountered?

Agree with Greg. Should be "uniquest".

RE: Whats the most unique engineering unit you've encountered?

In some parts of the US we have potholes/mile. I guess that would be a quality measurement of the paving, or of the budget office.

RE: Whats the most unique engineering unit you've encountered?

Cranky,
In Canada, the potholes are 1.6 times bigger than in the USA, so the distance unit comes out in the wash(board).

STF

RE: Whats the most unique engineering unit you've encountered?

I used to teach the three states of binary.
To use the coin analogy, the three states were Heads, tails and "In your pocket".
The course was a hands-on approach to designing and then wiring solid state logic devices.
When the circuit was unpowered, the memories and registers were "In your pocket".
When the circuit was powered up, the state of these devices was indeterminate.
The point was that when you powered up your circuit, you needed an initial reset signal to set the memories and registers to a known state.
It's always fun to explain the three states of binary to one of the 10 kinds of people who understand binary.
I could have taught Zero, One and Indeterminate but "In your pocket" was more likely to be remembered.
If, in the future, some students remembered the silly instructor who taught the three states of binary, great, they still remember the lesson.
Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Whats the most unique engineering unit you've encountered?

Not a unit but notation, and one that has changed.
@ originally meant 'at each' , as in 12 @ $2.34, the each matters.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Whats the most unique engineering unit you've encountered?

In some cases of binary, the third state is, the last known state, because the existing state is indeterminate.

RE: Whats the most unique engineering unit you've encountered?

Wrong page;

Quote (https://en.wikipedia.org/wiki/Three-valued_logic)

In logic, a three-valued logic (also trinary logic, trivalent, ternary, or trilean[1], sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Whats the most unique engineering unit you've encountered?

Well that one's got unsourced citations, too. Get to work!

The truth-tables you get from 3VL are really unbalanced. (a)OR(b) gives only 1 false result, 3 uncertain results, and 5 True results!
They lost me when they created the new expression (a)IMPLIES(b)...

STF

RE: Whats the most unique engineering unit you've encountered?

The point of my lesson was to emphasize the importance of including a system reset when the circuit was initially powered up.
The reset would ensure that the system was now a two state system.
It is quite easy to design a dependable circuit to disable all outputs until the initial system reset, without involving the third state.
Thanks for the references. I enjoyed reading them.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Whats the most unique engineering unit you've encountered?

We had a co-worker who read about ternary logic back in 1986-ish, and immediately began extolling its virtues and pushing the buzzwords around; EVERYONE but her recognized that 3-valued logic in a binary world was going to be a hard sell and hard do.

When she decided to go to a greener pasture, we had a great going away party, but somehow neglected to tell her about it; oops... winky smile

TTFN (ta ta for now)
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RE: Whats the most unique engineering unit you've encountered?

I can't find the article but I think there was a computer put together in year that had intentional errors in its calculations. A wrong close fast answer is better than a slow exact answer, I think the idea was.

RE: Whats the most unique engineering unit you've encountered?

Actually, there are a couple of instances where noise (error) is a good thing. In certain A/D operations, some added noise allows the digitization to have more variance, which can make it easier to get a more accurate answer after averaging. In some other cases, added noise allows digital filters to break out of limit cycle mode.

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RE: Whats the most unique engineering unit you've encountered?

Remember BCD? Each digit used only 10 of 16 possible counts for a waste of 6/16 or 37.5% waste. Still it had a lot of application interfacing with legacy 10 based counting devices.
Binary counting in ternary logic (There is not a great volume of base 3 legacy counting devices.) may reduce the wasted resource to only 1/3 or 33%.
But all things considered, I'd rather discuss the Smoot. Does anyone know how many "ears" there are in a smoot?

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Whats the most unique engineering unit you've encountered?

I haven't heard of Binary Coded Decimal in 30 years...

Dik

RE: Whats the most unique engineering unit you've encountered?

Now that you mention it I haven't said Binary Coded Decimal for over 30 years. Do you remember the "Switch Tail Ring Counter"?

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Whats the most unique engineering unit you've encountered?

Just vaguely... was helping one of my programming buddies with some timing diagrams for them, if memory serves... Used to be heavy into programming (a hobby) and often worked at the hardware level... I'm the only fool that hardwired an 8088, way back... about 30,000 solder connections...

Dik

RE: Whats the most unique engineering unit you've encountered?

I just ran across a strange unit here:
http://www.endurasim.com.au/wp-content/uploads/201...

They introduce the "snail".
It comes as a result of the definition of a pound being partly based on the foot, but engineering measurements usually expressed in inches. Hence, they include a 12 pound unit that they call the snail.
Then they convert it to slugs. spineyes

STF

RE: Whats the most unique engineering unit you've encountered?

Slug = weight in lbs / g sort of reminds me of an erg or a dyne (not sure which, haven't used them in 50 years), but in SI, a force/g

Dik

RE: Whats the most unique engineering unit you've encountered?

A YouTube star going by the handle 'AVE' (most of you would enjoy his cheeky and instructional videos) offers a ruler with "...the popular 'C.H.' scale...".

Explanation:
https://www.etsy.com/listing/464202928/one-rule-to...
2nd image, Zoom, extreme right hand end of ruler.

RE: Whats the most unique engineering unit you've encountered?

dik,

A slug is weight in pounds divided by gravitational acceleration in feet per second squared. The thing I like about doing calculations in English units is that I can avoid derived units like Newtons and slugs. As far as I am concerned, g=386in/sec2. I replace m with w/g. Using the metric system, I consider it absolutely critical to stick with the SI MKS units. Otherwise, weird things can happen.

--
JHG

RE: Whats the most unique engineering unit you've encountered?

drawoh:

Yup... g=32.2... ft/sec2

Dik

RE: Whats the most unique engineering unit you've encountered?

Quote (VE1BLL)


2nd image, Zoom, extreme right hand end of ruler.

Not exactly what you'd call politically correct, eh?

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Whats the most unique engineering unit you've encountered?

"Instrument set-ups per day" was my favorite.

I attended a school(Univ of MN) with a 5 year civil engineering curriculum. It was 250 credit course that included a 3 credit summer surveying class plus a 4 week field class at a school 180 miles away. It involved lake sounding and the usual land, highway and railroad surveying with different instruments - transits, levels, theodolites and electronic distance measuring. It got tiring setting up the equipment, so we decided to come up with a way to measure what we went through and used the set-ups concept of a measure of work of effort that day.

The second choice was the "drops per day" for the dropping and retrieving the depth sounding weights, while the other students got to measure the angles with transits to the boat from location to create a map via triangulation using flags as a signal when the depth weights were dropped. (pretty archaic)

After graduation, I did get to use surveying a couple of times in the aerospace industry.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

RE: Whats the most unique engineering unit you've encountered?

...like a BFR... a rock too big to step over, but, not big enough to warrant walking around...

Dik

RE: Whats the most unique engineering unit you've encountered?

How about the "miner's inch"? Defined differently in different jurisdictions, it is the water flow through a 1 square inch opening with a specified head (say 6 inches of water).

RE: Whats the most unique engineering unit you've encountered?

That's always been my favorite. Read all the way through to the last post thinking "Nobodies mentioned the miner's inch yet!".

So here's some other obscure units that can vary locally:

pony - small unit of liquor, in the US generally 1 US fluid ounce

rick - a stack of split firewood 4'high x 8' long by a "standardized length" usually 16". 1/3 cord or 1.2 steres. However, because the size of a rick has been manipulated by vendors, it is illegal to sell firewood by the rick in several US states.

rood - in some cases another word for a rod (16.5 feet) but in old England or Scotland sometimes it was 20 feet, 21 feet or even 24 feet.

And of course the ubiquitous barrel which depends on what you put in it. In the US a beer barrel is 31.5 gallons but in the UK it is 36 imperial gallons. An older British barrel equal to 1/2 hogshead is 26.25 imperial gallons. There are other official barrels defined in certain states that range from 30-40 gallons. Meanwhile, a barrel of petroleum is 42 US gallons around the world but a US dry barrel is 105 dry quarts unless it is a measure of weight in which case it again varies by contents. A barrel of flour holds 196 lbs, beef, fish and pork 200 pounds and cement 376 pounds.

----------------------------------------

The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

RE: Whats the most unique engineering unit you've encountered?

Has anyone mentioned the Unit yet?
Back in the days when sawdust was burned to heat houses, a unit of sawdust was a common measure. 1 unit = 200 cubic feet.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Whats the most unique engineering unit you've encountered?

When my family used to go on long bike rides in minnesota, my family had a unit of measurement called a green mile.

How long was your bike ride?

A green mile.

How long is a green mile?

About 3 Hours not including credits.

RE: Whats the most unique engineering unit you've encountered?

In that vein:
True story.
I was waiting for a train and the station agent came out to the waiting room and announced;
"I'm sorry, the train will be late. It was held up by a henway on the tracks."
"What's a henway?"
"Four or five pounds."

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Whats the most unique engineering unit you've encountered?

Here is another beauty: "biyearly" apparently means both "twice a year" and "every two years"

Change your oil biyearly. ponder

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: Whats the most unique engineering unit you've encountered?

I've seen kg/in^2 in requests for proposals. It is intended as a pressure.

I used to count sand. Now I don't count at all.

RE: Whats the most unique engineering unit you've encountered?

Quote (SandCounter)



I've seen kg/in^2 in requests for proposals. It is intended as a pressure.

Anathema! Kill it with fire

Given that kilograms are a unit of mass, not force, I am having a hard time visualizing mass per unit area. The time comes when you must stare blankly and stupidly at people, and ask them what it is they mean.

--
JHG

RE: Whats the most unique engineering unit you've encountered?

dgallup... you missed the Firkin... 9 gallons... and has different meanings depending on what you are storing...

I checked with wiki to see if 9 gallons was Imperial and found that a firkin for butter or cheese is 25 kg...

Dik

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