That state of metric conversion in the US

was

by

by

change

following

2m

it's

Right. n times m is p. Caffeine deficit.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation

Yes, that is a great shortcut. But my point isn't that there aren't great shortcuts. My point is that just plain going metric is a *ton* better, and I mean a ***metric*** TON!

BTW, the shortcut doesn't work so well when your fractions are decimal inches. That's just more crap on the pile, the mix of stuff we deal with in the inch/foot/mile/tsp/tbs/cup/pint/fifth/quart/gallon/oz/lb/ton/°F world we live in here in the USA.

You gotta love it! ...or leave it?

PS A friend is giving lectures on cold water safety and often says "mil" to mean mm. Not that anyone in the audience will get confused, but it hits a nerve in me.

--

Rick

I use FreePCB which doesn't have a lot of fancy features. But this is not a hard one to work with. Say you are routing on a 0.635 mm grid and approach a chip with pins spaced 0.5 mm. Pick up the route at the off grid pin heading back toward the unfinished trace. The first two vertices work back onto the grid one coordinate at a time including 45 degree angles. It works very well without a lot of programming (by the developer I mean). This is one of two programs I use that load in less than a second and open files in about the same amount of time. It even interfaces to an autorouter!

--

Rick

I'm unclear. When you say Philips is tapered, do you mean the profile of the flutes are tapered to the point at the end or the thickness of the flutes are tapered so they are more narrow at the edge than at the center?

I've never seen a Pozidriver or the corresponding screw... that I know of. I have used a few screws lately that seem to fit my drivers so well, I have trouble getting them out of the screw. This is using bits in a bit and drill collection from some years ago, Costco possibly. Tons of bits and drills of varying shape and sizes.

--

Rick

es?

d I

ful

so

s rule!

for

the

?

of

n

ll

6.4mm.

orld we

I much prefer metric. Decimal inches isn't bad. Fractional inches is the pits. Converting between the three crashes space probes, and wrecks the occasional part on my lathe.

--
Cheers, 
James Arthur

It's the constant thickness of the flutes that distinguishes pozidrive.

Have any old Tektronix gear around? As in 5K or 7K series lab scopes, or

400 series portable scopes, or TM500 test gear? _LOADS_ of pozidrive screws in them. As whit3rd said, using a phillips on these is a bad idea.

The Brat routes on a 1 mil grid. That can hit most anything.

We don't autoroute. It generally makes a mess of things.

Show us your boards!

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation

Actually, it was a Tek sig gen that had the screws the stuck on my philips driver. I'll take another look at them to see the hash marks.

--

Rick

I don't get it. What are you showing the boards for...?

--

Rick

What gets me is people saying 'mil' for 0.001"when they mean 'thou'. And MBOPD for a thousand barrels of oil per day but MMBOPD for a million.

Cheers

--
Syd

--
Attention.

think it's

I have tried a few, they are pretty ugly macros and not reliable.

?-/

100E7 is 10E8 and is always numerically 1E9 and completely unambiguous.

There may be some innumerate humans that can't read numbers in exponential notation but that is an entirely different matter.

Actually it *is* built in as a part of custom formatting of numbers in cells although the format syntax is cryptic so you might not guess it.

Sample data in engineering notation

1 1.0E+0 12 12.0E+0 123 123.0E+0 1234 1.2E+3 12345 12.3E+3 123456 123.5E+3 1234567 1.2E+6 12345678 12.3E+6 123456789 123.5E+6 1234567890 1.2E+9

The required default setting is Format Cells Custom "##0.0E+0" But the variable number of significant digits is not ideal!

Closest to being useful for engineers is "##0.0##E+0"

Alter the .0E bit to have at least enough digits. MS developers have no sense of engineers wanting a fixed number of mantissa digits displayed.

Business users don't care about accuracy and precision.

That is in Excel 2010 - exact syntactic sugar may vary with version no.

--
Regards, 
Martin Brown

Joerg schrieb:

Hello,

they simply used the base unit Meter of length and the base unit Newton of force to get a unit for pressure called Pascal. 1 bar was choosen to be 1e5 pascals to get a pressure unit to measure the atmospheric pressure as aproximately 1 bar. The units meter and newton very already defined and the natural air pressure at sea level is a fact. Nobody had to pick 1e5, this factor is the result of the definitions for the meter, the second and the kilogramm. Newton is defined from kilogramm, meter and second.

Bye

They did briefly try converting mmHg (ie torr) to pascals on hospital patient charts but it was quickly discontinued after nonsensical data was found with most patients blood pressure wrong by factors of 760/1E5.

Sometimes it makes sense to record critical data in the familiar traditional measure to avoid risk of corruption bad unit conversions.

A lot of hard vacuum kit is still calibrated in torr or rather small fractions thereof and I don't see it changing any time soon.

They didn't *pick* it any more than they picked 14.7lb/sq.in.

It just is what it is and in SI metric units by pure chance on Earth today it comes out at very close to 10^5.

Had they chosen some other metal as the kilogram reference material then a standard atmosphere would be a completely different number.

I fully expect torr and milliBar to coexist with the approved SI unit essentially forever. The former are far too convenient to get dropped.

The inch is 10% more than an atto Parsec by pure chance too.

IUPAC have the same problem with chemistry. They spend time teaching systematic names for chemicals to school children and the first thing they learn at university is that ethanoic acid is still called acetic and propan-2-ol is isopropanol if you want to be understood.

--
Regards, 
Martin Brown

Mil is a very old term for one thousandth of a US Dollar, or 1/10 of one cent which was and is still used in setting tax rates.

it's

You retards are so Office 2003!

sheesh! 2k7, 2k10, 2k13... ALL have advanced functions.

Losers like you do not.

Joseph = not reliable. For anything other than obsoleted "information" and convoluted, personally biased cracks.

then use the CUSTOM cell format selection, NOT the "scientific".

You can make a cell utilize such notation in a couple ways.

it's

Please do tell! I'd love to see Excel use SI multiplier prefixes. It doesn't, it can't, as far as I can tell.

(I suppose the 2k7 etc. refer to Excel versions? Shouldn't that be 2k007, 2k01 and 2k013 then? The 'k' is redundant, too.)

Jeroen Belleman