摘要 |
The invention comprises a detector arrangement adjustable for inclusion in a preventive protective system for a process plant comprising at least two sensor units (10, 10'), a unit (16a, 16b) for evaluating the output signal of each sensor unit and a calculation unit (17) capable of co-operating with the evaluating units (16a, 16b), the output signals of which calculation unit can cause an activating unit (18) to pass from a first position to a second position. One or more of a first category of sensor units (10) is designed, via its circuit (16a) for evaluating output signals, to be able to determine the energy content of a particle present. One or more of a second category of sensor units (10') is designed, via its circuit (16b) for evaluating output signals, to be able to determine the fire tendency or tendency to some other damage of the particle surroundings. The activating unit (18) is designed to pass from a first position to a second position only when the combined energy content and the tendency determined in said calculation circuit (17) indicate high risk of fire or other damage.
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