High Voltage Leak Detection


Since the establishment of the Tokyo based company in 1955, Nikka Densok has developed and produced many types of inspection machinery while keeping high quality and performance at top of their design criteria.

The Nikka Densok Pinhole Inspector has utilized the high voltage technology to support both the pharmaceutical and food Manufacturers to eliminate any chance of pinhole or product leakage. Within the last 40 years the development of the high voltage technology has contributed more than 1000 units sold worldwide.

Advantages of HVLD

There are variety of methods widely used within the pharmaceutical industry for the detection of pinholes, cracks and defective seals in various pharmaceutical packaging. These tests range from vacuum or pressure decay tests, to submerging the entire container into dye solution under pressure and visually inspecting the container for the presents of dye or more advanced vision systems to inspect for certain defects in the container. High Voltage Leak Detection (HVLD) System is the mos reliable, repeatable and productive inspection method having the following advantages:

  • Detection of 0.1 micro meter or smaller pinholes/cracks
  • Non-destructive Inspection Method
  • No secondary contamination to the product
  • 100 percent inspection at higher production speeds with increased reliability
  • 1uS/cm of WFI, dextrose and other low conductivity items can also be inspected
  • High voltage leak detection system achieves optimal performance in response to the increasing demand for CCIT (Container Closure Integrity Testing) for pharmaceutical containers.

Principle of Inspection

High voltage is applied to a hermetically sealed container made of non-conductive material.
If the pinhole or crack is present on the ampoule, the discharge current flows into the ampoule through the pinhole or crack.
The defective ampoule is detected by the differential of the current flow as measured in the intact ampoule.

Detection Performance Capability

Our high-voltage pinhole inspection machine is a technology that can reliably detect even 0.1µm holes. These tiny holes cannot be found by human eyes or visual inspection. Our pinhole inspection machines target Φ0.1µm diameter
holes, which are even smaller than Φ0.2µm of the filling filter mesh diameter, to test the integrity of container closure.

An example of hole detected by using our high voltage system
= Pinhole 0.5µm photomicrograph