LightThru – Broken Core Inspection

LightThru is a system primarily designed for the manufacturing of cylinder heads and engine blocks, where production takes place through conventional aluminum alloy gravity casting in semi-permanent sand core molds. LightThru can be fully integrated into the production process. Its major advantages are its modularity and the option to integrate other types of inspections into a single device.

Detection of defects in cylinder heads and engine blocks

LightThru probes that measure the signal passing through the casting can determine the total amount of transmitted light and the route from where the signal is coming.

Manufacturing aluminum castings with inner cores has various defects that may have disastrous consequences for the final product. The sand core sometimes breaks or is otherwise damaged, and the cavity becomes completely or partially blocked after the core is removed. The damaged channel adversely affects the engine’s life and performance. The detection of damaged core channels reduces the risk of potential car accidents and also clients’ complaints.

Advantages and benefits:

100% automated inspection of production

Very short inspection cycle times

Inspection of branched channels in a casting

Localizing the defect within a casting

Greater range of inspection in the casting compared with conventional solutions

Reduced investment costs when integrating multiple measurements in one facility

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Detection Options:

  • Full blockages of channels caused by sand core defects
  • Improper de-coring of channels
  • Penetration of the metal into the core

System Parameters:

Measuring signal dynamic range: 100 dB
Standard cycle time: 26s part to part (as low as 16s for special applications)
Max number of senders: 64
Max number of receivers: 64
Detection of full blockages: 100% guaranteed
Detection of partial blockages: Depending on application, usually starting from 50%

Method of Measurement

The LightThru system operates on the principle of measuring light passing through the channels of the casting. The light is transmitted via LEDs and measured by photodiodes. A system of special probes designed for each product is separately inserted into the casting. Each probe includes transmitters and/or receivers. By measuring the signal between selected transmitter-receiver pairs, the system evaluates whether the passability of that part of the casting falls within expected tolerances, or if the product was damaged. Measurement takes place separately after each transmitter so defects can be clearly localized. When the channels are completely blocked, the signal decreases to zero. Should the signal fall below the standard process variability, the system will suspect partial blockage. The basic advantage LightThru has over the air flow-based system is the ability of independently measuring branched channels. Individual transmitters and receivers are positioned on the probes to be optimally directed into each channel, enabling them to be independently measured.

Alternative Technologies

LightThru is often installed as complementary technology to Nanocameras for inspection of internal channels.


  • Accurate visual inspection
  • Detection of partial blockages
  • Front/back light configuration
  • Inspection of nearby surfaces only


  • Inspection of long curved channels
  • Localization of defects in parts
  • Only full blockage detection
  • Sensitive to changing surface conditions

Integration Options

LightThru can be fully integrated into the production process.

There are various mechanical designs based on the type of manufacturing process. Major advantages are its modularity and the option to integrate other types of inspections into a single device.

  • Separated measuring device with manual loading
  • Inline device with conveyor-based handling
  • Robotically operated automatic cell
  • Integrated with Nanocameras, MS 3D measuring, surface inspections, IIT threat condition and other measuring systems in a single device