Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
Rain Gauge
3
VAN WALT
Monitoring your needs
1.2 General
The e+ RAIN sensor is an intelligent sensor that consists of a specic sensor section as well as a so-
called datalogger that houses the micro-electronics. The datalogger has an internal memory for
storing the measurements but also provides the means for reading the digital data. To make this
1.4 Measuring section
The rain gauge is part of the e+ RAIN sensor and is manufactured from UV-proof
synthetic material. It furthermore has an aerodynamic design which ensures
that measurements suffer as little as possible interference from the wind. The
system operates on the so-called ‘tipping bucket’ method, in which rain is
captured via a funnel and poured into a basin that is xed on a hinge. A pre-
determined amount of rain results in the bucket tipping and emptying itself. Brief
contact results with a switch. In this way the amount of rain equals the number of
switch contacts during a specic time unit. The rain gauge is tted with a 5-pole
connector for connection with the datalogger.
The raingauges tipping bucket mechanism is immobilised before shipping to prevent damage
in transit. To release the mechanism, remove the funnel from its base by unscrewing the three
thumbscrews. Remove the piece of foam from under the bucket mechanism. This foam may be
saved and used whenever the raingauge is moved
1.3 Datalogger
The datalogger is designed around a
microprocessor that performs the role of saving
periodical measurements in the memory and
enables a connected device to read the stored data. The signal
that the sensor part delivers to the interface is converted into data
that can be processed by the microprocessor. The microprocessor
records the data in the memory with a sample speed, based on the
internal Real Time Clock (RTC). It is possible by means of available communication channels,
namely the optical connector and the IrDa link, for a device that has been connected to
communicate with the microprocessor and read the data stored in the memory or adjust
settings such as the sample speed, for instance. The datalogger of the e+ sensor has 2 measuring
channels and the memory range is divided proportionally over the available channels. The
memory has the capacity to store 30.000 measurements per channel.
possible the datalogger has an optical connector for a
communication cable or a readout unit or an IrDa interface for
communication by means of an IrDa readout unit. This offers the
advantage of intercompatibility, reliable transfer of data and
the possibility of stand-alone use.
