Add explanation why we adjust the update duration for mb3

miio/airpurifier_miot.py

@@ -46,7 +46,7 @@
     # AQI (siid=13)
     "purify_volume": {"siid": 13, "piid": 1},
     "average_aqi": {"siid": 13, "piid": 2},
-    "aqi_realtime_update_duration": {"siid": 13, "piid": 9},  # see #1281
+    "aqi_realtime_update_duration": {"siid": 13, "piid": 9},
     # RFID (siid=14)
     "filter_rfid_tag": {"siid": 14, "piid": 1},
     "filter_rfid_product_id": {"siid": 14, "piid": 3},
@@ -402,6 +402,9 @@ class AirPurifierMiot(BasicAirPurifierMiot):
     )
     def status(self) -> AirPurifierMiotStatus:
         """Retrieve properties."""
+        # Some devices update the aqi information only every 30min.
+        # This forces the device to poll the sensor for 5 seconds,
+        # so that we get always the most recent values. See #1281.
         if self.model == "zhimi.airpurifier.mb3":
             self.set_property("aqi_realtime_update_duration", 5)