5
Introduction to Radiographic Testing
Employer Certification
1. Certification of nondestructive testing personnel is the responsibility of the employer.
2. Personnel may be certified when they have completed the initial training, experience, and examination
requirements described in the employer’s written practice.
3. The length of certification is also stated in the employer’s written practice.
Central Certification
1. ASNT developed the ASNT Central Certification Program (ACCP) for the third-party certification of
nondestructive testing personnel.
2. This certification program is intended to meet or exceed the requirements of ISO-9712.
Basic Math Review
Digit Strings
Digit strings are set with spaces (per IEEE/ASTM SI 10, paragraph 3.5.4.2), not commas, as follows:
l 123
l 1234
l 12 345
l 123 456.789
Exponents
1. An exponent is the numerical symbol used to indicate the raising of a base number to some indicated
power, showing how many times the base number must be multiplied by itself.
2. For example, in the case of 23, 3 is the exponent and 2 is the base. This means that 2 is multiplied 3 times,
as follows: 2 × 2 × 2 =8.
3. Even letters designating variables may represent an exponent and base—for example, pq. In this case, p is
the base and q is the exponent.
4. Any number raised to the power of 0 is 1. For example, 100 =1.
Multiples
Exponents can reduce the number of zeros needed to express a numeral through use of multiples. Common
prefixes involving multiples and their symbols include:
l 103 =1000 =1 kilo (k)
l 106 =1 000 000 =1 mega (M)
l 109 =1 000 000 000 =1 giga (G)
Introduction to Radiographic Testing
Employer Certification
1. Certification of nondestructive testing personnel is the responsibility of the employer.
2. Personnel may be certified when they have completed the initial training, experience, and examination
requirements described in the employer’s written practice.
3. The length of certification is also stated in the employer’s written practice.
Central Certification
1. ASNT developed the ASNT Central Certification Program (ACCP) for the third-party certification of
nondestructive testing personnel.
2. This certification program is intended to meet or exceed the requirements of ISO-9712.
Basic Math Review
Digit Strings
Digit strings are set with spaces (per IEEE/ASTM SI 10, paragraph 3.5.4.2), not commas, as follows:
l 123
l 1234
l 12 345
l 123 456.789
Exponents
1. An exponent is the numerical symbol used to indicate the raising of a base number to some indicated
power, showing how many times the base number must be multiplied by itself.
2. For example, in the case of 23, 3 is the exponent and 2 is the base. This means that 2 is multiplied 3 times,
as follows: 2 × 2 × 2 =8.
3. Even letters designating variables may represent an exponent and base—for example, pq. In this case, p is
the base and q is the exponent.
4. Any number raised to the power of 0 is 1. For example, 100 =1.
Multiples
Exponents can reduce the number of zeros needed to express a numeral through use of multiples. Common
prefixes involving multiples and their symbols include:
l 103 =1000 =1 kilo (k)
l 106 =1 000 000 =1 mega (M)
l 109 =1 000 000 000 =1 giga (G)