Subd. 3. Practice of professional engineering. Any person shall be deemed to be practicing professional engineering within the meaning of sections 326.02 to 326.15 who holds out as being able to perform or who does perform any technical professional service, such as planning, design or observation of construction for the purpose of assuring compliance with specifications and design, in connection with any public or private structures, buildings, utilities, machines, equipment, processes, works, or projects wherein the public welfare or the safeguarding of life, health, or property is concerned or involved, when such professional service requires the application of the principles of mathematics and the physical and applied engineering sciences, acquired by education or training, and by experience.