During the whole Florida debacle, it seemed that some of the counties were using optical card readers, which I presume to be the same technology used for standardized tests like the SAT (“Please use a #2 pencil to completely fill in…”). This reminded me of something I’ve always wondered: what is so special about #2 pencils on these forms? As opposed to, say, black pens or softer #1 pencils? Does it have something to do with mark density? And has that limitation been overcome?
Softer pencils make darker marks but smear and break more easily. I would guess the equipment is calibrated to the darkness made by a #2 pencil, and so it’s safer just to have everyone using the same thing.
BTW, I’m pretty sure a #1 pencil is harder lead, and makes lighter marks. #3 is softer. Another way of rating leads, from hardest to softest is 2F, F, HB, H, B, 2B. (Or something like that.) HB is equivalent to #2, but damned if I know what it stands for.
The #1 pencils I’ve used have made very dark marks, darker than #2 and also much harder to erase completely.
For the record, around here, we use optical scanners for voting that utilize a pen. Presumably it is slightly harder to change the mark, once made (and therefore slightly more fraud resistant).
I bet the optical scanners for test taking could be calibrated to use a pen, but don’t for precisely the opposite reason as above. As for #2’s, I haven’t a clue.
I used a #1 pencil on my SAT last month, it seemed to work fine. I managed to get over 1200, dunno if it was due to the pencil or not.
This seems sensible: the #2 pencil restriction has never been a technological limitation, just a convenient standard. The confusion is that ignorant teachers and test proctors always presented it as a technological limitation. (The mind boggles at how anal some people get when asked to proctor a standardized test.)
I work with mark sense (optical) scanners all the time.
The are actually two types of scanners.
Some work by light transmission; they shine a light through the paper towards sensors which detect the marks. These will work when you use just about any type of writing instrument (or even White-Out, believe it or not) as long as the marks are opaque enough. They would not work for a sheet that had response area to bubble in on both sides, for obvious reasons.
The other and far more common type works by reflection; light is reflected from the marks back to sensors. This is where you need the #2 pencil, as the machines are calibrated to the reflective properties of that specific hardness of graphite. You can generally get away with using a #1 or #3 pencil, however.
Wow. I’ve been pondering this very thread question for years, and just yesterday figured that (our school’s) Scantrons must work by reflection of pencil marks. Thank you for confirming my thought! For the record, I figured this because I discovered one can scribble all over a Scantron with a dark pen and still have only the pencil marks count. So Origato’s info is confirmed, by recent tests.
IIRC, the original mark sensing machines made by IBM used pairs of little wire brushes to detect graphite within the little boxes by measuring conductance between the brushes as the card passed through the machine. This is not a very robust technology and you needed to be fairly precise in making your mark and consistent in depositing graphite to make it work, hence the instructions to be precise and the requirement to use a no. 2 pencil.
I made it through college using an HB lead in a mechanical pencil for about a zillion tests, despite the instructions to use #2.
Here in Alabama, we vote with felt tip pens on scanned ballots. (they kick out imediately if you vote for two presidents, for example, so’s you can correct that problem before you leave the polls).
I was chatting online with the head of our state’s election equipment certification commission. He says that these devices (known as “mark sense” devices since they sense marks) will work with any device that makes a dark mark. The current mark sense devices work optically, and will sense any dark mark of any kind, pen, felt tip, etc. They just say to use a #2 pencil because that is the most common standard pencil.
#2 means the same thing as HB. On some #2 pencils, they even print HB next to the 2.
What, It took you three years to come up with that?
Here’s a little chart I found printed on the back of my box of Pentel lead:
Soft (darker imprint): 2B, B
Medium (general use): HB, F, H
Hard (lighter imprint): 2H, 3H, 4H, 5H, 6H
So 2B is the softest and 6H is the hardest. I prefer to use 2B on my mechanical
pencil. It takes a lot less effort to write with the soft lead.