What physical principles does the Digital Coating Thickness Gauge use to measure coating thickness?
Publish Time: 2024-11-06
Digital Coating Thickness Gauge is a precision instrument used to measure coating thickness. They measure coating thickness based on a variety of physical principles.
1. Magnetic principle
Principle: Magnetic coating thickness gauges use magnetic or electromagnetic principles to measure coating thickness.
Application: Suitable for measuring non-magnetic coatings (such as paint, plastic, enamel, etc.) on magnetic substrates (such as steel).
Measurement method:
Magnetic induction method: The coating thickness is inferred by the magnetic force of the magnet attracting the substrate under the coating. The thicker the coating, the smaller the magnetic force between the magnet and the substrate.
Magnetic eddy current method: Use an electromagnetic coil to generate a magnetic field, and infer the coating thickness by measuring the change in the induced current in the electromagnetic coil.
2. Eddy current principle
Principle: Eddy current coating thickness gauges use eddy current effects to measure coating thickness.
Application: Suitable for measuring non-conductive coatings (such as paint, anodized layers, etc.) on non-magnetic substrates (such as aluminum, copper, zinc, etc.).
Measuring method:
Eddy current method: By emitting an alternating electromagnetic field to the substrate, eddy currents are induced. The coating thickness will affect the intensity and phase of the eddy current, thereby inferring the coating thickness.
3. Ultrasonic principle
Principle: Ultrasonic coating thickness gauges use the characteristics of ultrasonic waves propagating in coatings and substrates to measure coating thickness.
Application: Suitable for measuring coatings on various substrates, including metals, plastics, composite materials, etc.
Measuring method:
Ultrasonic reflection method: Emit ultrasonic pulses to the interface between the coating and the substrate, measure the time and intensity of the ultrasonic waves reflected from the coating surface, and calculate the coating thickness by the sound speed and time.
4. Optical principle
Principle: Optical coating thickness gauges use the principles of light reflection, interference or diffraction to measure coating thickness.
Application: Suitable for transparent or translucent coatings (such as thin films, coatings, etc.), as well as measurement occasions that require high precision.
Measuring method:
Interference method: Use the interference phenomenon of light to infer the coating thickness by measuring the interference fringes of light of different wavelengths.
Spectral reflectance method: Calculate the coating thickness by analyzing the spectral characteristics of the reflected light on the coating surface.
5. Electrolysis principle
Principle: The electrolytic coating thickness gauge uses the electrochemical reaction in the electrolysis process to measure the coating thickness.
Application: Applicable to metal coatings on metal substrates, such as electroplating layers, anodized layers, etc.
Measurement method:
Coulomb method: Calculate the coating thickness by the amount of electricity consumed in the electrolysis process. The coating thickness can be inferred from the time and current intensity consumed by the electrolysis.
Digital Coating Thickness Gauge measures coating thickness based on a variety of physical principles, including magnetic principle, eddy current principle, ultrasonic principle, optical principle and electrolysis principle. Each principle is applicable to different types of coatings and substrates. Choosing the right measurement method can ensure accurate and reliable coating thickness measurement.
