Why can non-contact safety features not compensate missing limitation of operational forces
If a radiation protection gate exceeds the limited operational forces during the closing force measurement, safety cannot be established by sub-sequently installing non-contact safety features. That is mainly based in the applicable standard EN ISO 13855: Safety of Machinery – Arrangement of protective devices, in relation to the approaching speed of body parts. When applying this standard, the distance from the non-contact safety units to the dangerous edge are of such dimension that a person could easily fit in the space in between. Applying the above mentioned standard secures the gate system against tumbling in or reaching in by hand by a person. Another disadvantage of the non-contact safety feature is , that the closing edges can often not be secured up to a height of 2,5 m. In radiation therapy it is furthermore to be expected, that ailing people have to pass through the gate.
Ailing people most often are not able to recognize dangerous situations fast enough in order to react properly. Due to the physical conditions of these people, already low forces could cause major injuries. For these above mentioned reasons, all power operated radiation protection gates supplied by us, fulfil the safety requirements for the closing and operational forces.
Safety of existing radiation protection gates
Near radiation protection gates the presence of employees is very likely. Therefore the Industrial Safety Regulations have to be applied, which require in article 4, paragraph 2 that work materials have to meet state of the art requirements.
The Federal Court of Justice has confirmed in its verdict 5261/210, dated March 2, 2010, that power operated gates must be upgraded after a certain period to correspond to the state of the art.
As the product standard EN 13241 had already been bindingly implemented in Germany in May 2005, the “Safety Standards for radiation protection gates” have also to be applied for existing radiation protection gates.
Consequently radiation protection gates, which exceed the acceptable closing forces, must not be approved.