6.1 As provided for by 6.4.6.3 of this Code, in
the case of the E2, E3 or D2 test cycles, the minimum number of load
points shall be such that the combined nominal weighting factors,
as given in 3.2 of this Code, are greater than 0.5.
6.2 In accordance with 6.1, for the E2 and E3
test cycles it would be necessary to use the 75% load point plus one
or more other load points. In the case of the D2 test cycle, either
the 25% or 50% load point shall be used plus either one or more load
points such that the combined nominal weighting factor is greater
than 0.5.
6.3 The examples below give some of the possible
combinations of load points that may be used together with the respective
revised weighting factors:
| Power
|
100%
|
75%
|
50%
|
25%
|
| Nominal
weighting factor
|
0.2
|
0.5
|
0.15
|
0.15
|
| Option
A
|
0.29
|
0.71
|
|
|
| Option
B
|
|
0.77
|
0.23
|
|
| Option
C
|
0.24
|
0.59
|
|
0.18
|
| Plus
other combinations that result in a combined nominal weighting factor
greater than 0.5. Hence use of the 100% + 50% + 25% load points would be
insufficient.
|
| Power
|
100%
|
75%
|
50%
|
25%
|
10%
|
| Nominal
weighting factor
|
0.05
|
0.25
|
0.3
|
0.3
|
0.1
|
| Option
D
|
|
|
0.5
|
0.5
|
|
| Option
E
|
|
0.45
|
|
0.55
|
|
| Option
F
|
|
0.38
|
0.46
|
|
0.15
|
| Option
G
|
0.06
|
0.28
|
0.33
|
0.33
|
|
| Plus
other combinations that result in a combined nominal weighting factor
greater than 0.5. Hence use of the 100% + 50% + 10% load points would be
insufficient.
|
6.4 In the case of the C1 test cycle, as a minimum,
one load point from each of the rated, intermediate and idle speed
sections shall be used. The examples below give some of the possible
combinations of load points which may be used together with the respective
revised weighting factors:
| Speed
|
Rated
|
Intermediate
|
Idle
|
| Torque
|
100%
|
75%
|
50%
|
10%
|
100%
|
75%
|
50%
|
0%
|
| Nominal
weighting factor
|
0.15
|
0.15
|
0.15
|
0.1
|
0.1
|
0.1
|
0.1
|
0.15
|
| Option
H
|
|
0.38
|
|
|
0.25
|
|
|
0.38
|
| Option
I
|
|
|
|
0.29
|
|
0.29
|
|
0.43
|
| Option
J
|
0.27
|
0.27
|
|
|
|
|
0.18
|
0.27
|
| Option
K
|
0.19
|
0.19
|
0.19
|
0.13
|
|
0.13
|
|
0.19
|
| Plus
other combinations incorporating at least one load point at each of rated,
intermediate and idle speeds.
|
6.5 Examples of calculation of revised weighting
factors:
-
.1 For a given load point, revised weighting factors
shall be calculated as follows:
-
y% load = nominal weighting factor at load y • (1/(sum
of the load factors for load points where data was acquired))
-
.2 For Option A:
-
75% load: revised value is calculated as: 0.5 • (1/(0.5
+ 0.2)) = 0.71
100% load: revised value is calculated
as: 0.2 • (1/(0.5 + 0.2)) = 0.29
-
.3 For Option F:
-
75% load: revised value is calculated as: 0.25 • (1/(0.25
+ 0.3 + 0.1)) = 0.38
-
.4 The revised weighting factors are shown to
two decimal places. However, the values to be applied to equation
19 of this Code shall be to the full precision. Hence in the Option
F case above the revised weighting factor is shown as 0.38 although
the actual calculated value is 0.384615. Consequently, in these examples
of revised weighting factors the summation of the values shown (to
two decimal places) may not sum to 1.00 due to rounding.