history and reference Meaning Of ÷ In Dimentioning

[73touring]

Im a bit sheepish asking this as I KNOW that I Should KNOW this!!

Im using the WS manual to measure the tollerences of my spare oil pump before I put it in storage and the measurments are something like Outer/Inner Rotor (mm) .(0.12 ÷ 0.30)  I wass expecting a plus minus, it the ÷ something to do with runout?

 

Ive been trying to look up the interweb to find the answer but google doesnt  seem to include that symbol when searching!

 

Thanks,

 

(Sheepish) Rob.

 

 

[73touring]

Someone please put me out of my misery!

[peterschop]

The Haynes manual states the between the tips of the inner and outer rotors should be from 0.12 to 0.20 mm. What manual are you using? 

[02Les]

Im a bit sheepish asking this as I KNOW that I Should KNOW this!!

Im using the WS manual to measure the tollerences of my spare oil pump before I put it in storage and the measurments are something like Outer/Inner Rotor (mm) .(0.12 ÷ 0.30)  I wass expecting a plus minus, it the ÷ something to do with runout?

 

Ive been trying to look up the interweb to find the answer but google doesnt  seem to include that symbol when searching!

 

Thanks,

 

(Sheepish) Rob.

That "style" of stating the tolerance was from an earlier version of the Blue Repair Manual (3.73).

The later version (9.75) shows  mm (in)    0.12....0.20 (0.0047.....0.0079)

Gap inner/outer rotor should be between the two numbers.

[FB73tii]

I've always interpreted the division symbol in the BMW 2002 factory repair manual as a range. Here is an example for engine compression on page 11-0/3

 

Compression test

 

Good....above 10.5 atm

Normal.....9.5 ÷ 10.5 atm

Poor....below 9.0 atm

 

EDIT: Ah, I was typing at the same time Les was. My factory Blue book must therefore be the older version. --Fred

Edited July 5, 2014 by FB73tii

[73touring]

I must have the earlier version also then. In that case my spare oil pump is very good!

[Simeon]

Probably a European thing like using a comma as a decimal point.

[Solarphil]

I took it to be the typographical equivalent of "plus or minus" because it looks like the two symbols overlaid on each other.  Don't know if that's correct and I have no proof, just figured it "aughta be"