User`s guide

Chapter 4 ______________________________________________________________ Maintenance
VAISALA______________________________________________________________________ 137
Anemometers
Periodic Maintenance
Cleaning
Heavy contamination in the cups, such as bird dropplets or ice will
deteriorate the accuracy of the anemometer. Clean the cups when
necessary.
Testing Proper Operation
The sensor will hold its accuracy in all conditions for 1 year. If the rains
are mostly casual and moderate, and the atmospheric corrosion is
typical, the sensor accuracy will remain for 2 years.
However, the ball bearings must be checked once a year and the sensor
shaft rotated manually. To do this, remove the cup wheel. To ensure
proper operation, the shaft should spin smoothly and it should not create
any detectable noises.
Replacing Bearings of WAA151
Replacement of the ball bearings should only be done by a trained
technician. To replace the ball bearings of WAA151, follow the
procedure below and refer to Figure 110 on page 140.
1. Open the cup wheel fixing screw with a 2-mm Allen key. Remove
the cup wheel assembly.
2. Loosen the hex nut of the connector with a 22-mm tool.
3. Loosen the three pan head screws at the bottom of the sensor body
with a 7-mm tool.
CAUTION
The cup wheel fixing screw has been treated with sealant. Do not
remove the fixing screw to ensure perfect sealing after reassembling.
CAUTION
Be careful not to bend the connector pins.