Product type: MEL3
A fully automatic EL inspection system for solar modules

A Security-monitored lid for easy access
B Automatic flap
C Easily removable service covers
D Operator panel
E Electrical cabinet

The Efficiency is an outstanding automatic test system for solar modules based on the electroluminescence process.

Fully automated and reliable failure detection on multi- and mono-crystalline cells are outstanding features. It is designed to be engaged before or after the lamination process in highly automated production lines.

As well as offline in the laboratory, the EL Efficiency is a highly precise El inspection system.

With enhanced functionality like the AEVAL-Software (Advanced EVALuation), even the most complex quality guidelines can be implemented.

The “Power Loss Estimation” (PLE) software feature is a reliable forecast, about the maximum power loss that may be caused in future filed operation by defects detected in cells today.

The pi4 “Repair Station Manager” (RSM) supports the operator effectively to replace defective cells and strings.


  • The machine concept of in-line EL inspections systems incorporates all our 20-years experience in the area of machine engineering.
  • Pi4 is an image processing specialist. We have developed a unique technology for reliable defect detection for mono and multicrystalline cells.
  • Easy to use machine software.
  • Secure and precise handling of modules, even unlaminated and with glass thickness down to 2 mm.
  • Short cycletimes
  • Ambient light protection with automatic entry and exit doors.
  • Precise automatic contacting of modules.
  • Only high quality components from well-known manufacturers are used.
  • Flexible adapting of line interfaces and machine security integration.
  • Convenient and flexible access to the test data, e.g. via an implemented database.

Technical specifications:

  • EL Inspection with up to 72 MP per module
  • Modules sizes up to 2000mm x 1050mm, sunny side down, long edge leading
  • Cycle time from 18s with parallel pull-in and push-out
  • Modules pre lamination, laminated with or without frame
  • Conveyor height 920 - 1050mm, up to 400mm/s
  • Automatic contacting on connectors or J-boxes
  • Cell size M0 (156mm)
  • Mono or multicrystalline cells
  • Modules with up to 72cells (6x12)
  • EL-Power 0-65V DC /0-10A
  • Signal interface to the conveyors befor and after the tester via ProfiBus, ProfiNet, digital I/O etc
  • MES connection via database
  • Signal interface to a higher-level safety control
  • Power supply 380-400V AC 50-60Hz TN-S-System
  • Compressed air 6 bar
  • Machine frame 2380mm x 1450mm


  • Code reader
  • Accessories for offline use
  • Software “AEVAL”
  • Software “Power Loss Estimation”
  • Software “Repair Station Manager”