'Calculate the humidity at the (cold) calibration point.'

def _calc_moldindicator(self):

    if ((None in (self._dewpoint, self._calib_factor)) or (self._calib_factor == 0)):
        _LOGGER.debug('Invalid    inputs    -    dewpoint:    %s,    calibration-factor:    %s', self._dewpoint, self._calib_factor)
        self._state = None
        return
    self._crit_temp = (self._outdoor_temp + ((self._indoor_temp - self._outdoor_temp) / self._calib_factor))
    _LOGGER.debug(('Estimated    Critical    Temperature:    %f    ' + TEMP_CELSIUS), self._crit_temp)
    alpha = ((MAGNUS_K2 * self._crit_temp) / (MAGNUS_K3 + self._crit_temp))
    beta = ((MAGNUS_K2 * MAGNUS_K3) / (MAGNUS_K3 + self._crit_temp))
    crit_humidity = (math.exp((((self._dewpoint * beta) - (MAGNUS_K3 * alpha)) / (self._dewpoint + MAGNUS_K3))) * 100.0)
    if (crit_humidity > 100):
        self._state = '100'
    elif (crit_humidity < 0):
        self._state = '0'
    else:
        self._state = '{0:d}'.format(int(crit_humidity))
    _LOGGER.debug('Mold    indicator    humidity:    %s', self._state)
