Introduction Of NDT Technology
Acoustic Partial Discharge Analyzer
What is it?
We use infrared to detect light that the eye cannot see and Acoustic Partial Discharge Analyzer on the other hand are used to detect high frequency sound that the ear cannot hear. Acoustic Partial Discharge Analyzer is sensitive to sounds beyond the limits of normal human hearing. The best human ears can hear noises in the range of 20 hertz to about 20,000 hertz (20kHz). Acoustic Partial Discharge Analyzer provides engineers with a method of detecting sounds greater than 20kHz; the detectors start at approximately 20 kHz and work upward to sounds as high as 100 kHz.
How does it works?
Loose electrical connections emit characteristic sounds that are beyond the range of the human ear. The Acoustic Partial Discharge Analyzer provides a method of converting inaudible sounds to sounds and tones that match our hearing capabilities.
Electricity flashing over an insulator makes a crackling sound that can be detected even when there are no visible signs of arcing. A typical use for the device is to detect loose or arcing connections inside an enclosed Cabinet or Switch Board. It will determine if the situation is safe or if the equipment should be de-energized before opening.
All high-voltage switchgear should be checked with Acoustic Partial Discharge Analyzer prior to opening or starting a project. Acoustic Partial Discharge Analyzer can identify loose connections that thermography (infrared) could miss, in particular for High Voltage equipment which operates at much lower current. Such connections often do not produce enough heat to be detected, or the surrounding heat source masks the problem.
The Capacitive EMF Partial Discharge Analyzing and Computer Aided Acoustic Partial Discharge Analyzing is designed to detect partial discharge sources in high voltage (HV) Plant. If no discharges are detected, this does not necessarily imply that an item of HV Plant is discharge free. Discharge sites often have dormant periods and insulation structures can fail through causes other than those attributable to partial discharge. Therefore, it is also important that such partial discharge test should be carried out regularly i.e. 6-monthly or 12-monthly depending on how critical this HV plant is.