This measures rain by the drop as well as by the tradional 'tip'. We can configure it either with an SDI12 serial data interface or an integral logger with cellular communications.

Allowing simultaneous measurement of rain intensity and total rain fall in the same instrument, the SRIG represents a major advance in rainfall measurement instrumentation.

The NIWA Smart Rain Intensity Gauge SRIG) combines three distinct technologies.

  • The core of the gauge is an industry standard tipping bucket gauge (TBRG) that records rain events in multiples of 0.2mm.
  • Feeding this is a rain intensity gauge that forms and counts individual drops of water so measuring rain events to the nearest drop (equivalent to 0.003mm of rain). The third part of this gauge is a micro-powered interface circuit that counts the drops and the tips along with a number of associated parameters and provides access to them over an SDI-12 interface.
  • The result is an extremely versatile rain gauge that can be connected to any environmental data logger supporting an SDI-12 interface. An optional built-in cellular enabled logger can also be supplied which, along with internal battery and flexible solar panel, creates a truly selfcontained telemetered multi function rain gauge.

Typical Applications

  • Stand alone rain gauge with integral telemetry for real time remote data access.
  • Weather station enhancement
  • RIG replacement where total rainfall is also required.


  • Standard 0.2mm TBRG
  • Rain intensity gauge with a resolution of 0.003mm
  • Standard SDI-12 interface.
  • Optional inbuilt logger with cellular communications (GPRS or CDMA)
  • Integrated flexible solar panel & battery option.
  • Very low power consumption.
  • Detection of RIG overflow or streaming events.

Frequency Asked Questions

Q: What happens if the drop former blocks? A: The water is diverted down the overflow to be measured by the TBRG beneath and is detected by the overflow electrodes. Q: What happens in very heavy rain? A: At some point the drop former will begin to stream and the drop detector will be unable to distinguish between drops. However all rain will be still be accurately recorded by the TBRG Q: How do I know if the RIG has been streaming? A: The quality flags that accompany every reading will indicate this condition, they also indicate if an overflow has occurred. Q: Does the drop size vary with rain rate? A: There is a gradual reduction in drop size from low rain rates up to the point where streaming commences. This variation is approximately 10% up to 50mm per hour of rain. Q: At what point does the RIG start to stream. A: This occurs at a rain rate of about 80mm per hour. Q: Can I add other sensors to my telemetered SRIG. A: Yes, the integral data logger is fully programmable and may be connected to a variety of other sensors including soil temperature, soil moisture, air temperature etc.


Rain receiver diameter: 200mm TBRG resolution: 0.2mm TBRG accuracy: +/- 1% (at 12mm/h) Drop resolution: 0.03mm (nominal) Overall height: 470 mm OPTIONS Internal Battery: 12V 2Ah Internal Logger: Unidata NRT Telemetry: GPRS or CDMA Solar panel: 1W 50mA flexible