At 06:57 PM 3/3/01 -0500, Duane Hague wrote:
For example, on QFPs the same manufacturer will refer to a part as having
a 25 mill (0.025 inch) pin pitch and then provide a package drawing in
metric showing a pitch of 0.65 millimeters Typical (and the other
dimensions on the drawing indicate
At 04:59 PM 3/3/01 -0800, Mike Ingle wrote:
I strongly reccomend that you get a sample part from the manufacturer and
measure it yourself. Also if their documentation is confilcting, a call
wouldn't hurt.
Good advice. Actually, rereading the original post, it looks like there is
only one
On 09:43 AM 3/6/01 +1000, [EMAIL PROTECTED] said:
Depends on the format of the original. 0.1inch is far more accurate than
2.54mm
because 0.1 = 0.10.
No. That is incorrect.
Otherwise, it would have been published as 0.10.
Though we presume it to be true, by virtue of
On 12:23 PM 3/6/01 -0500, Steve Smith said:
I would never assume any dimension to be dead accurate
as you must allow for rounding off and tolerances.
Ah...tolerances...Now why exactly would we care about those?
After all, we're in a metric age, where everything is by default exact
to the nth
Point taken if it is in the decimal form but 0.1 inch is 1/10 of an inch and if
you think
of it as a fraction rather than a decimal, the fraction has got to be a more
acurate
measurment than a rounded decimal.
___
Clive Broome
IDT
As the guilty party who triggered this digression, I feel constrained to
contribute. The change evidently occurred when I was out of the country
(military stuff) and I failed to notice it for over thirty years. My 1966
Handbook of Chemistry Physics gives US Inch = 25.40005 millimeters and
At 08:50 AM 3/7/01 +1000, [EMAIL PROTECTED] wrote:
Point taken if it is in the decimal form but 0.1 inch is 1/10 of an inch
and if you think of it as a fraction rather than a decimal, the fraction
has got to be a more acurate measurment than a rounded decimal.
No, there is no difference
Using 2/3 of an inch or .67 of an inch, its obvious which one is the more
accurate. Maybe
fractions rather than rounded decimals used in conversions would allow better
accuracy.
___
Clive Broome
IDT Sydney Design Centre
