From an occupational safety point of view the market launch of hand-held laser processing devices (HLDs) should be closely correlated to the qualification of machine safety. In order to meet demands concerning a safe design of HLDs, a project was started in 2007, to both develop and evaluate safety concepts for HLDs and to qualify technical measures for HLD laser safety.
On the basis of risk assessments, both safety requirements on architectures of safety controls and safety related parts of control systems are defined and prototype control systems are built. Beneath criteria claimed in standards, e.g. DIN EN ISO 13849-1, safety related parts are also investigated concerning practicality for use in HLDs, and concerning malfunctions, signal propagation delays and costs. A number of miniaturized sensors with different active principles and safety levels are tested with regard to their qualification for the respective type of HLD.
For HLDs positioned on a work piece, investigations cover contact and non-contact sensors such as mechanical switches, inductive, capacitive and ultrasonic sensors. Especially for freely operated HLDs (e.g. for cleaning applications), non-contact optical sensors and movement sensors (MEMS, Gyros) to isolate the laser beam under fault conditions (such as slipping) are tested. Furthermore, sensors to detect faults in HLD beam guidance are qualified.
Results will be edited in guidelines for manufacturers and users of HLDs.