Method and device for hydrometeor detection

A method for measuring hydrometeors, in which method

• the mechanical impulses of hydrometeors falling on a detection surface, and which exceed a predefined threshold value, are measured,
• the initiation of the measurement is triggered in connection with pulses exceeding the threshold value,
• in connection with triggering, at least one initial parameter, such as amplitude or the rate of change of the pulse, is defined from the impulse,
• characterized in that, after the first measurement, the time is measured which elapses before the parameter has reached a predefined value relative to the initial value of the parameter, and this time is used as a characteristic parameter in filtering.

A method for measuring hydrometeors, in which method

• the mechanical impulses of hydrometeors falling on a detection surface, and which exceed a predefined threshold value, are measured,
• the initiation of the measurement is triggered in connection with pulses exceeding the threshold value,
• in connection with triggering, at least one initial parameter, such as amplitude or the rate of change of the pulse, is defined from the impulse, characterized in that
• the triggering level of the hydrometeor-signal detection circuit (3) is adjusted on the basis of the wind velocity, in such a way that the amplitude of spurious signals caused by the wind remains below the triggering level.

A measuring device for detecting hydrometeors, which includes

• a detector part (I), which, in turn, includes
• a detection element (6), for detecting impacts caused by hydrometeors,
• an amplifier circuit (5), for amplifying the output signal of the detection element (6),
• a limit-value circuit (3), for triggering the measurement of impulses exceeding a specific signal level, and
• a processor part (2) for processing the triggered signals, characterized in that
• the detector part (1) is arranged to perform continual measurement, in order to define the threshold value of the impulse,
• the processor part (2) is arranged to be excited to measurement operations only when the threshold value is exceeded, in order to minimize the power consumption of the measuring apparatus, and that
• the device includes means for filtering out mechanical disturbances of the signal during processing, on the basis of one or more characteristic features of a hydrometeor signal.