All of our rain gauges (except our Snow Rain Gauge) does not need any power supply. The working princible is a magnet that affects a reed switch which opens and closes when the Tipping Bucket tips. Thus, when connecting a data logger / controller, the signal goes HIGH or LOW when the Tipping Bucket tips - depending on which PCB you choose.
PCB 9602 = Normally Open or Normally Closed.
PCB 9601 = Normally Open.