Corona Camera and Thermal Imager Leave a comment

Thermal Imager Camera

Thermography, also called thermal imaging, is a technique used to produce an image of invisible infrared light. In addition, objects produce this light with the use of a thermal imaging camera. Thermal imaging cameras provide quick scanning of a surface that is environmentally friendly and nondestructive. This allows for the rapid detection of defects or future problems to reduce preventive maintenance and troubleshooting times.

What do Thermal Imager Cameras Capture?

Thermal imaging cameras do not capture temperature. They capture the IR (infrared) energy transfer from an object to the environment. This produces a real-time image in a color palette where cooler objects are darker and hotter objects are brighter. Infrared energy is created by the vibration of molecules and atoms. It behaves similar to visible light in that it can be absorbed, emitted, refracted, and reflected. The more the molecules and atoms move, the higher the temperature of the object.

Uses of Thermal Imaging Cameras

  • Substation electrical inspections
  • Locate radiant heating pipes or wires
  • Thermal heat loss inspections in buildings
  • Detect insulation leaks in refrigeration equipment
  • Detect thermal patterns on boiler tubes
  • Mechanical bearing inspections
  • Flat roof detection for buildings
  • Locate potential areas for mold growth

These cameras are primarily used where identifying thermal patterns can be used to diagnose a condition or find something. Also, this could include poor insulation or an overloaded electrical circuit.

What is Corona? 

Corona is known as a partial discharge. It’s a type of localized emission that results from transient gaseous ionization. It is in an insulation system when the voltage stress (voltage gradient) exceeds a critical value. Corona has the capability of causing systems to fail by degrading insulators. In addition, the ionization is typically localized over a portion of the distance between the electrodes on the system. Corona can occur within the voids in insulators as well as the insulator interface.

Effects of Corona

Corona is bad for insulation because it degrades it and can lead to insulation failure. The effects of corona are permanent, and failure can happen without warning. 


  • Ultraviolet radiation
  • Light
  • Ozone
  • Sounds (hissing or cracking)
  • Salts (white powder deposits)
  • Nitric and various other acids
  • Mechanical erosion of surfaces by ion bombardment
  • Carbon deposits
  • Heat

Corona Cameras

These cameras are based on (UV) detection principles. In addition, they respond to radiation in the spectral range of about 180 to 260 nm. This range is less sensitive to natural background radiation sources like sunlight and cosmic radiation. Daycor Corona Cameras are ready with very high sensitivity. Also, they can detect partial discharges with 7.7dBµV RIV level and 1 pC PD level from 10 meters away. Also, they can detect corona from 150-300 meters. This makes them ideal for handheld inspection or vehicle/areal surveys.

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