| The data is not received from the sensor. |
The sensor is mechanically damaged. |
Check the cables and connectors. |
| After removing the connector's hexagon nut, the connector is bent, which breaks the connection wires. |
Check the connector. |
| The sensor is not powered properly. |
Make sure that the supply voltage is from 9.5 ... 15.5 V DC. |
| Some Vaisala products, for example, WAT12, switch power on to the
sensor only for a very short period (200 ... 500 s). |
Make sure that the sensor output rises above Uin - 1.5 V
at the end of the power pulse. |
| The sensor shaft is covered with ice and snow. |
The heating element does not function. |
Send the sensor to Vaisala for repair. See Product returns. |
| The heating element is not properly connected. |
Open the sensor and make sure that the heating element outlet is
connected to the connector on the printed circuit board. See Replacing consumables. |
| The output from the connector pins C to H do not have the right code or are not
at the proper level. |
The printed circuit board is damaged. |
Replace the printed circuit board. See Replacing consumables. |
| Current consumption is either less than 17 mA or more than 25 mA when the shaft
is rotated mechanically. |