Table 6.

Advantages and disadvantages of selected measurement techniques

Technique	Principle	Advantages	Disadvantages
Visual Testing	Mechanical-optical	Low cost, Minimum training	Time consuming, Low resolution, low Repeatability and high error
Radiographic Testing	Penetrating radiation	Non-contact	Time consuming, Hazardous
Nuclear magnetic resonance	Magnetic field	Quick, can be used in routine analysis	Expensive
Ultrasonic Testing	Sonic-ultrasonic	Non-contact	Single point measurement, Limited to acoustics impedance
Thermal imaging	Temperature and heat flow measurements	Non-contact, No harmful radiation, High portability, Real-time imaging	Requires training, Expensive
X-ray topography	Electromagnetic spectrum wavelength (<1 nm)	Non-contact	Time consuming, Hazardous, not applicable to bulk flowing products
Hyperspectral imaging	Spectroscopy	Multi-constituent information	Requires training, Expensive
		Sensitivity to minor components