|HP-9G unit conversions|
Message #1 Posted by Herman on 17 Feb 2006, 12:25 p.m.
The HP-9G seems like a nice little machine, so I checked into its specs at hp.com. Its "up to 24-digit internal calculation accuracy" is definitely way beyond enough for me.
HP's info about the 9G's unit conversion capabilities is
On page 2 of the above document is a table displaying the units used in the HP-9G CONV menu.
The text underneath the table says that "some units are exact (e.g. feet, inch, gallon) while others are provided up to 13 digits of accuracy".
Looking at the table, I see that indeed several units (amongst which gallon) are off in their last (13th) digit. However, yard and pound are quite off the mark and only are specified with 8 to 9 digits accuracy.
Now, why can't HP get a yard as 0.9144 m (by definition) built into this calculator, instead offers us 0.9144000009144 m ?
And why can't HP get a pound as 0.45359237 kg (by definition) in it ? The 9G says "1 lb = 0.4535923772575 kg". Using Excel to figure out how many HP-9G correct ounces are in an HP-9G off-the-mark pound, it says "16.00000026"... That's a whopping 8 digits of accuracy, or 'back to the early seventies' !?
At hp.com I filled in an inquiry form about these HP-9G unit conversion inaccuracies, then got an 'email undeliverable' message... That's why I'm posting here and hope to get an answer from a Hewlett Packard expert.
Well in due time I'll probably get one anyway, because it's a handy and quite powerful calculator that you don't have to lock up at night. Meanwhile, I will continue to use my good old [censored] fx-4500P, and keep the correct conversion units in an Excel sheet.