if co2_level < 500:
            self.notification.level_c = 0
        elif co2_level < 1500:
            es_time = PreProcessing.estimate_time(gateway_id, device_id, module_id, 1500, None)
            self.notification.level_c = 1
        elif co2_level < 2500:
            es_time = PreProcessing.estimate_time(gateway_id, device_id, module_id, 2500, None)
            self.notification.level_c = 2
        elif co2_level < 4000:
            es_time = PreProcessing.estimate_time(gateway_id, device_id, module_id, 4000, None)
            self.notification.level_c = 3
        else:
            self.notification.level_c = 4