1. Conformity-of-Production
maximal number of tests: N=16
based on average and variation of test results
average of all test results < limit - margin
decreasing margin with the increasing number of tests
start with N=3, stop at N=16
based on test variation
with the number of tests
the spread in the average
decreases

2. Test each emission component against limit value
COP
Test each emission component against limit value
Start with N=3 tests, determine average emission value X and standard deviation S, from the individual measurements xi:
average: 𝑋= 1 𝑁 𝑖=1 𝑁 𝑥 𝑖
standard deviation: 𝑆= 1 𝑁−1 𝑖=1 𝑁 ( 𝑥 𝑖 −𝑋) 2
Pass if:
𝑋<𝑙𝑖𝑚𝑖𝑡 −𝑆
Fail if:
𝑋≥𝑙𝑖𝑚𝑖𝑡− 𝑁−3 13 ∗𝑆
Continue testing till decision (maximal N=16 tests)
assuming normal
probability distribution:
pass at ~ 84% confidence
incremental change:
with N=3: X ≥ limit
with N=16: X ≥ limit-S

3. average number of tests
COP
Simulations of the procedure with respect to limit = 1, homogeneous distributions
average value
min
max
pass rate
average number of tests
0.980
0.95
1.01
88.8%
5.1
0.995
0.98
44.9%
5.7
1.005
0.99
1.02
4.0%
3.2
1.000
15.4%
4.1
0.950
0.80
1.10
43.2%
5.8
0.70
1.30
14.9%
1.20
29.4%
5.0
large spread: high fail rate
limited test burden

4. The application of COP in type-approval testing
Options:
only Test Mass Low testing (limited burden)
only Test Mass High testing
both Test Mass High and Test Mass Low testing (completeness)
Any vehicle production model in the CO2 family (mixed problem of testing and interpolation procedure)