Let’s look at their features:

Full table
pedestal delta second stimulus Weber L diff
5 50 55 10.00 10.41 -0.41
5 45 50 9.54 10.00 -0.46
5 40 45 9.03 9.54 -0.51
5 35 40 8.45 9.03 -0.58
5 30 35 7.78 8.45 -0.67
5 25 30 6.99 7.78 -0.79
10 50 60 6.99 7.78 -0.79
10 45 55 6.53 7.40 -0.87
5 20 25 6.02 6.99 -0.97
10 40 50 6.02 6.99 -0.97
10 35 45 5.44 6.53 -1.09
15 50 65 5.23 6.37 -1.14
5 15 20 4.77 6.02 -1.25
10 30 40 4.77 6.02 -1.25
15 45 60 4.77 6.02 -1.25
15 40 55 4.26 5.64 -1.38
10 25 35 3.98 5.44 -1.46
20 50 70 3.98 5.44 -1.46
15 35 50 3.68 5.23 -1.55
20 45 65 3.52 5.12 -1.60
5 10 15 3.01 4.77 -1.76
10 20 30 3.01 4.77 -1.76
15 30 45 3.01 4.77 -1.76
20 40 60 3.01 4.77 -1.76
20 35 55 2.43 4.39 -1.96
15 25 40 2.22 4.26 -2.04
10 15 25 1.76 3.98 -2.22
20 30 50 1.76 3.98 -2.22
15 20 35 1.25 3.68 -2.43
20 25 45 0.97 3.52 -2.55
5 5 10 0.00 3.01 -3.01
10 10 20 0.00 3.01 -3.01
15 15 30 0.00 3.01 -3.01
20 20 40 0.00 3.01 -3.01
20 15 35 -1.25 2.43 -3.68
15 10 25 -1.76 2.22 -3.98
10 5 15 -3.01 1.76 -4.77
20 10 30 -3.01 1.76 -4.77
15 5 20 -4.77 1.25 -6.02
20 5 25 -6.02 0.97 -6.99
pedestal delta second stimulus Weber L diff
5 5 10 0 3.0103 -3.0103
10 10 20 0 3.0103 -3.0103
15 15 30 0 3.0103 -3.0103
20 20 40 0 3.0103 -3.0103

A more visual way of understandind their relation

Pedestal = 10

Pedestal = 10

Pedestal = 10


We can see that the larger the second stimulus
in oppose to the first pedestal stimulus,
so do both fractions, L and Weber, converge.