Yesterday, a fellow blogger wrote:
I’ve got a question for you on writing style and SI units. Most of my blog posts use meters and MHz and not a lot else. I am pretty good at using MHz consistently but have been working on improving meters.
For example, I’ll often say “on the 2m band”… some of my old writing had “2M band” which is incorrect but lately I’ve been pretty consistent with “20m”, “2m”, and “70cm”.
The issue I am looking at now is that the SI style guide from NIST and others says there should be a space between the 2 and m, as in “2 m band”. In some usage, this looks OK but in others it just doesn’t look right to me. For example, a title might be “How to Use the 2m Band”…which seems better than “How to Use the 2 m Band”.
So then I looked at your blog for inspiration and it has a lot of “2m” and “40m”, etc. It looks like you do that consistently.
Any thoughts or suggestions?
I replied:
Honestly, I agree with the NIST style guide. Technically, it should be written as the “2 m band.” That was the way we’d do it at Test&Measurement World. Think of it this way: m is an abbreviation for “meters,” and you wouldn’t write it 20meters, would you?
Having said that, most amateur radio radio operators will usually write it as “20m” or “2m.” As you note, I’m guilty of doing that in my blog posts. That’s incorrect, but more than understandable by hams, who are my audience.
I’ll also note that QST will usually spell out “meters” rather than simply using an “m.” So, you get the “80-meter band” or “80 meters.” And, thinking a little more about this, when referring to an amateur radio band, it probably would be more correct to include the word band, i.e. write “80-meter band” instead of just “80 meters.”
Perhaps what I’d advise is to perhaps do that when writing for an amateur radio audience and referring to a particular ham band, “80m,” 40m,” “20m,” etc. is acceptable, even if incorrect. When referring to a length, however, there should be a space between the number and the unit.
But, now that you bring it up, I think that I’m going to be more strict about this usage, and I’m going to spell out “meters” instead of just using “m.” There’s no need to get lazy.
By default, I would follow the style guide(s). I still have an old SI guide from the 70’s when metric was being introduced to the US, and referred to it often. One item that trips up a lot of folks is ‘kHz’ (not ‘KHz’). Most interactive spellers (Word, Google, etc) now get it right, but I still run across this occasionally. The abbreviation for ‘kilo’ is ‘k’, not ‘K’. It’s a bit odd, because all the other abbreviations for units greater than 1 are upper case, but not in this case.
In IT work, there is a similar confusion about ‘kb’. Is that a kilo-bit, or a kilo-byte? Some usage I’ve seen is to use an upper case ‘B’ for byte, e.g. 32 kB. It looks odd, and I’ve seen ‘KB’ or ‘Kb’, which is incorrect, used in a lot of data sheets, although Google is completely happy with those misuses. Also, in IT work, does ‘k’ mean 1000, or 1024? It usually means the latter, and I’ve seen usage like KiB or MiB to indicate ‘thousands of bytes’, or ‘millions of bytes’, instead of 1024 x 1024 bytes – 1,048,576 bytes. This is common on hard drive size specs, where a so-called 500 GB drive is actually 500 GiB (500,000,000,000 Bytes), which is actually a lot less than 500 GB (500x1024x1024x1024 Bytes). Drive sizes seem to have followed a progression of non-powers-of-two sizes, as well (100 MB, 250 MB, 500 MB, 1 TB, etc).
How about the pronunciation of GHz? The only time I heard it pronounced correctly from any formal source was a Microsoft talking dictionary in about 1990. A professor of mine in electrical engineering taught that the metric system came from France and the prefix giga was pronounced ghiga or shiga. Of course then it was cycles not Hertz. That talking dictionary and two or three individuals I have known are the only ones who pronounce it that way in my 50 years as an engineer. I don’t think even the French do now.