Determining the Value of the Check Digit

When you save a record on the Automotive Containers form, the Check Digit field is populated automatically, to validate the accuracy of the Owner Code, Equipment Category ID, and Container Serial Number values. The Check Digit is only populated when those fields are not empty.

Each letter of the owner code, the equipment category identifier, and each numeral of the serial number is consecutively allocated a numerical value.

For the owner code or equipment category, these equivalent numeric values are allocated:

Letter Equivalent Value Letter Equivalent Value
A 10 N 25
B 12 O 26
C 13 P 27
D 14 Q 28
E 15 R 29
F 16 S 30
G 17 T 31
H 18 U 32
I 19 V 34
J 20 W 35
K 21 X 36
L 23 Y 37
M 24 Z 38

The serial number is restricted to the digits 0-9.

Weighting Factor

The weighting factor is a method of subjectively increasing the relative importance of one item over another. Each numerical equivalent is multiplied by a weighting factor in the range 2^0 to 2^9. The weighting factor 2^0 is applied to the first letter of the owner code, and then in increasing powers of 2, rising to 2^9 for the last digit of the serial number.

Value of the Check Digit

This table indicates the check digit value corresponding to the remainder value of division effected in conformity with 0. To avoid the duplication resulting from the value zero being assigned as a remainder of both 10 and 0, we recommend that serial numbers resulting in remainders of 10 should not be used.

Remainder Check Digit
10 0
9 9
8 8
7 7
6 6
5 5
4 4
3 3
2 2
1 1
0 0

The serial number is restricted to the digits 0-9.

Sample Calculation

This example shows a sample owner code, equipment category ID, and serial number, and then provides equivalent and weighting factors for each letter and numeral. The last table shows the product of the columns in the Equivalent Factors table and the Weighting Factors table.

Owner Code = ZEP

Equipment Category ID = U

Serial Number = 003725

Full ID
Z E P U 0 0 3 7 2 5
Equivalent Factors
38 15 27 32 0 0 3 7 2 5
Weighting Factors
1 2 4 8 16 32 64 128 256 512
Product of columns in Equivalent Factor and Weighting Factors
38 30 108 256 0 0 192 896 512 2560

The sum of all the products in this table = 4592

The sum divided by the modulus 11 = 417 5/11

The remainder is 5. See the Value of the Check Digit table above to determine that the check digit is 5 in this case.

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