UF4001 Diode Graph

[bostonman]

I have a question about the graph for a UF4001 diode (which is similar to other graphs - see attached).

When I read these graphs, they only have nine horizontal lines between major numbers which confuses me because it should be ten.

Have I been missing something.

[Someone]

Time you went for an eye check at the optometrist?

[squadchannel]

ten lines?

[bostonman]

I wasn't sure if the very bottom was line 0 or line 1, however, the next one between 0.1 and 1 is nine lines (unless of course I'm really that blind).

[Konkedout]

This is a logarithmic graph.  There is no zero.  As you approach zero the magnification increases and you never quite get there. 

[mikerj]

Even if this was a linear scale you won't have 10 lines between the major values.  You don't get ten millimetre marks between each cm mark on a tape measure.

[xavier60]

Whichever way the lines are counted, there is one less on the log scale.

[SteveThackery]

Whichever way the lines are counted, there is one less on the log scale.

Eh? Why?

Oh, sorry: you mean because the counts go from 1 to 10 (say), not 0 to 10. 👍

[xavier60]

Yes, another example.
Say a linear scale goes, 10,11,12,13,14,15,16,17,18,19,  20.  ; eleven lines.
a Log scale might go, 10,20,30,40,50,60,70,80,90,  100.    ; ten lines.

[bostonman]

I may still be confused.

The 1 - 10 increments I understand (from 0.01A to 0.1A) but what about 0.1A to 1A?

Does the 0.1A line start at point 1 even though it ended at 10 (see my marked up version)? I was counting 1-10, and then starting the next line at 1 which made it nine increments.

[xavier60]

When counting increments, don't count the starting point.
From .01 to 0.1, there are 9 increments.
From 0.1 to 1, there are 9 increments.

[SteveThackery]

I may still be confused.

The 1 - 10 increments I understand (from 0.01A to 0.1A) but what about 0.1A to 1A?

Does the 0.1A line start at point 1 even though it ended at 10 (see my marked up version)? I was counting 1-10, and then starting the next line at 1 which made it nine increments.

I haven't entirely understood your question, but this might help. It seems confusing at first because the major marks on the graph go up in powers of ten, rather than in tens. There are nine increments between each major mark. I've put the major marks in bold, the rest are normal text.

etc...
100
90
80
70
60
50
40
30
20
10
9
8
7
6
5
4
3
2
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.09
etc....

The increments are the gaps between the lines. For example: 1 to 2, 2 to 3, 3 to 4, and so on up to 9 to 10. Count them and you will see there are nine increments. When it comes to lines (minor marks) between the major marks there are eight lines:

1 2 3 4 5 6 7 8 9 10

So between each major mark (power of ten) there are eight minor marks (lines) and nine increments (gaps).

[TimFox]

When labeling a logarithmic axis, common options include, for the lines between 1 and 10:
All integers 2 through 9
Only 2 and 5
Only 3
2, 3, 5, 7
Normal graph paper has all of the lines at 2, 3, 4, 5, 6, 7, 8, and 9.
I use an expensive graphing software ("Grapher" from Golden Software) that I like because I can use arbitrary endpoints for log axes, such as 3.4 to 25, to fit my actual data range.

[PCB.Wiz]

I may still be confused.

Yes.
Try simply writing the actual current next to every line, and see if you are a line short, or a line to many, or if there is exactly the correct number of lines to fit 2 3 4 5 6 7 8 9