• PG4i, a “Made in Italy” solution appreciated all over the world
    PG4i, a “Made in Italy” solution appreciated all over the world

PG4i, a “Made in Italy” solution appreciated all over the world

December 2020

PG4i are autonomous rain gauges with a collection surface of 400 cm2 which, thanks to an integrated 3G modem, are able to measure, locally record and autonomously send data relating not only to accumulated rainfall, but also to its intensity per minute to an FTP server, all without any connection to an external datalogger.

This new stand-alone sensor, designed to facilitate a distributed, high-density monitoring of rain measuring points, was born in 2019. In order to verify the functionality and robustness of the first prototypes, CAE has launched a structured campaign to test them. Some organizations, including Italian universities and administrations which are particularly active in the field of rain measurement, have made agreements with our company and participated in the test campaign.

The Consortium for Parma’s Land Reclamation is one of the organizations that carried out these first tests. It is also thanks to the resulting technical contributions that the PG4i project has gradually improved, becoming therefore a finished product.

Among the first to adopt the innovative instrument, were not only the Consortium itself, but also several other administrations in Italy and abroad, which have kindly provided the pictrures accompanying this article.

The new PG4i have found wide application both in the monitoring network of the Hydro-meteorological Institute of the Republic of Serbia, and in the local Early Warning system of the City of Belgrade.

The stand-alone sensor has proven to work well also in the Maldives islands, in completely different environmental conditions than in the Balkans, and where it provides information to the Maldives Meteorological Service network.

Thanks to the efficient on-board controlling electronics, the intensity of rain, calculated by the instrument on the basis of the tilting of the balance, indicates the real intensity of rain for each minute, expressed in mm/h and with a final resolution of 0.1 mm/h.

The maximum error of our products, in their standard version, remains below 3% up to 350 mm/h, below 5% between 350 and 500 mm/h, and below 10% between 500 and 600 mm/h.

At customer's request, it is possible to select even more performing products, as they all are “Made in CAE”.

Overcoming one of the limits of weighing rain gauges, PG4i rain gauges measure with precision from the first minute following the detected phenomenon and are therefore especially suitable for timely measurement of rainstorms.

PG4i rain gauges produced by CAE are compliant to “Class A” according to the UNI EN 17277:2020 standard and therefore are the best available on the market for such equipment.

PG4i are particularly easy to maintain due to their self-emptying tilting technology and redundant reeds. They can report possible malfunctions before they cause the interruption of the measurements thanks to innovative built-in diagnostics aiming at checking:

- the clogging of the funnel that conveys the water to the moving parts;
- the correct angle of the instrument mouth with respect to the ground: “electronic bubble level”;
- the correct functioning of the sensing elements (reeds) counting the movements of the moving parts;
- the good condition of the tilting and moving parts.

Thanks to the low consumption, standard batteries guarantee uninterrupted operation for very long periods of time and, at the same time, highly simplify installation operations. PG4i do not require solar panels or mains electric power supply.

PG4i are simple and intuitive: you just have to insert batteries and register on the website http://support.cae.it to start receiving data.

Rain gauges can also be customized and configured via web or locally by physically connecting to the tool.

Customizations include:

- FTP service;
- 3G connection service;
- mode and frequency of sending data.


In 2020, UNI EN 17277:2020 standard became part of the European regulations for the sector. A result of the experience gained by the Meteorological Service of the Italian Air Force and the University of Genoa in the context of the World Meteorological Organization (WMO), it represents the first European reference for defining the performance of data collecting rain gauges.

In order to carry out and certify an effective and correct calibration of its rain gauges according to this standard, CAE was the first to produce an "automatic" calibration machine for data collecting rain gauges, which incorporates what the UNI EN ISO 10012: 2004 standard specifies.

It is therefore possible to check and calibrate the rain gauge with constant flows at various rain intensities, as required by the standard. This device allows CAE to certify the rain gauges placed on the market (with a specific calibration certificate), guaranteeing its customers the certainty of purchasing a certified product of high quality, precision and reliability.

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