Return current readings, as a dictionary with:
            duration -- the duration of the measurements, in seconds;
            cpm -- the radiation count by minute;
            uSvh -- the radiation dose, exprimed in Sievert per house (uSv/h);
            uSvhError -- the incertitude for the radiation dose.

def status(self):
        """Return current readings, as a dictionary with:
            duration -- the duration of the measurements, in seconds;
            cpm -- the radiation count by minute;
            uSvh -- the radiation dose, exprimed in Sievert per house (uSv/h);
            uSvhError -- the incertitude for the radiation dose."""
        minutes = min(self.duration, MAX_CPM_TIME) / 1000 / 60.0
        cpm = self.count / minutes if minutes > 0 else 0
        return dict(
            duration=round(self.duration / 1000.0, 2),
            cpm=round(cpm, 2),
            uSvh=round(cpm / K_ALPHA, 3),
            uSvhError=round(math.sqrt(self.count) / minutes / K_ALPHA, 3)
            if minutes > 0
            else 0,
        )