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Radiographic Testing Instructor Guide l LESSON 1
As Low As Reasonably Achievable Dose
The goal of radiation safety is to keep all radiation exposures as low as reasonably achievable (ALARA).
There are three basic principles to minimize radiation exposure:
l Time: Minimize time duration working with radiation sources.
l Distance: Increase distance between the source of radiation and the technician and others.
l Shielding: Provide shielding of a suitable material density to attenuate X- and gamma rays.
Qualification of Nondestructive Testing Personnel
1. One of the most important aspects of any nondestructive testing method is that all personnel be trained,
qualified, and certified. Personnel must be familiar with the technique, equipment, test objects, and
procedures.
2. The American Society for Nondestructive Testing (ASNT) publishes guidelines for training and
qualifying nondestructive testing personnel in Recommended Practice No. SNT-TC-1A: Personnel
Qualification and Certification in Nondestructive Testing.
3. ANSI/ASNT CP-189: ASNT Standard for Qualification and Certification of Nondestructive Testing
Personnel is similar to SNT-TC-1A in terms of training, experience, and examinations however, the
standard provides minimum requirements that may not be changed.
Levels of Qualification
1. There are three basic levels of qualification applied to nondestructive testing personnel and used by
companies that follow SNT-TC-1A and CP-189: NDT Levels I, II, and III.
2. An individual in the process of becoming qualified and certified to NDT Level I is considered a trainee.
Certification of Nondestructive Testing Personnel
1. It is important to understand the difference between two terms that are often confused within the field
of nondestructive testing: qualification and certification. Qualification is a process that should take place
before a person can become certified.
2. The actual certification of a person in nondestructive testing to an NDT Level I, II, or III is written
testimony that the individual has been properly qualified.
3. Proper qualification and certification are extremely important because the process of testing performed
by certified nondestructive testing personnel can have a direct impact on the health and safety of every
person who will work on, in, or in proximity to the equipment or assemblies being tested.
4. Poor work performed by unqualified personnel can cost lives, especially in RT.
Radiographic Testing Instructor Guide l LESSON 1
As Low As Reasonably Achievable Dose
The goal of radiation safety is to keep all radiation exposures as low as reasonably achievable (ALARA).
There are three basic principles to minimize radiation exposure:
l Time: Minimize time duration working with radiation sources.
l Distance: Increase distance between the source of radiation and the technician and others.
l Shielding: Provide shielding of a suitable material density to attenuate X- and gamma rays.
Qualification of Nondestructive Testing Personnel
1. One of the most important aspects of any nondestructive testing method is that all personnel be trained,
qualified, and certified. Personnel must be familiar with the technique, equipment, test objects, and
procedures.
2. The American Society for Nondestructive Testing (ASNT) publishes guidelines for training and
qualifying nondestructive testing personnel in Recommended Practice No. SNT-TC-1A: Personnel
Qualification and Certification in Nondestructive Testing.
3. ANSI/ASNT CP-189: ASNT Standard for Qualification and Certification of Nondestructive Testing
Personnel is similar to SNT-TC-1A in terms of training, experience, and examinations however, the
standard provides minimum requirements that may not be changed.
Levels of Qualification
1. There are three basic levels of qualification applied to nondestructive testing personnel and used by
companies that follow SNT-TC-1A and CP-189: NDT Levels I, II, and III.
2. An individual in the process of becoming qualified and certified to NDT Level I is considered a trainee.
Certification of Nondestructive Testing Personnel
1. It is important to understand the difference between two terms that are often confused within the field
of nondestructive testing: qualification and certification. Qualification is a process that should take place
before a person can become certified.
2. The actual certification of a person in nondestructive testing to an NDT Level I, II, or III is written
testimony that the individual has been properly qualified.
3. Proper qualification and certification are extremely important because the process of testing performed
by certified nondestructive testing personnel can have a direct impact on the health and safety of every
person who will work on, in, or in proximity to the equipment or assemblies being tested.
4. Poor work performed by unqualified personnel can cost lives, especially in RT.