The sensor that calls you in the middle of the night when frost threatens, on up to 10 numbers. Installed in 5 minutes, no gateway.
User manual (PDF) All documentation
The S31-NB is the most widely deployed frost alarm sensor in the FURGO range — the one fitted, among others, on fruit farms in the Drôme. Its job: measure the dry and wet-bulb temperature every 15 minutes, and call you — actually call you, on the phone — when your threshold is crossed.
On a clear night of radiative frost, it is the wet-bulb temperature that shows the real cooling of the bud, sometimes 2 to 3 °C below the dry temperature. The S31-NB computes it continuously from temperature and relative humidity; that is the value you set your alert on, to start the sprinklers or the frost towers at the right moment — neither too early (diesel and sleepless nights for nothing) nor too late.
No gateway, no pairing, no app to install: the sensor arrives with its SIM activated and transmits as soon as it is switched on. The 8500 mAh battery lasts 3 to 5 seasons; it can then be replaced for a few dozen euros — just like the SIM top-up. That is our definition of low-tech: repairable hardware, with no subscription rent.
After 3 to 5 years depending on use, you replace the battery and top up the SIM plan — a few dozen euros, not a subscription. The sensor and the platform keep working.
No. The sensor transmits directly over multi-network GSM, anywhere a phone gets signal. Nothing to install, nothing to configure.
The S31-NB runs on a long-life battery (3–5 years) — the recommended choice in fruit growing. The S31-CS has a solar panel and a smaller battery (20–40 days without sun).
From the platform, you set your thresholds (for example +1 °C wet-bulb) and the numbers to call. They can be changed at any time, including at 3 a.m. from your phone.
Going further This sensor answers the need “Frost alarm for orchards and vineyards” — read the full page (solution comparison, 5-year total cost, real cases).
The same frost alarm sensor as the S31-NB, with a built-in solar panel that recharges the battery every day. It calls you when frost threatens, on up to 10 numbers.
Météo-France forecasts for the exact spot of your plot, with a frost-risk indicator, right on your dashboard. Nothing to install.
The long-life battery that gives your FURGO sensor another 3 to 5 years of battery life. Swapped in 15 minutes with a simple screwdriver.
