WMT700 measures the time it takes for an
ultrasonic signal to travel from one transducer to another. Therefore, the accuracy of the
sensor depends on the distance between the transducers and the time-of-flight measurement
circuit, which uses a crystal oscillator for its time reference.
If necessary, you can verify the distance
between the transducer arms with an optional verifier. You can order the verifier from
Vaisala as an accessory.
Vaisala recommends that you test the proper
operation once a year or if you suspect that the transducers may have been damaged. The
sensor arms may be bent or the rubber on the transducers may be damaged. Make a visual check
to verify if there is physical damage.
You can perform the test either in the field or in a laboratory.
| CAUTION Do not perform the
test when the wind speed is more than 10 m/s (22 mph) or when there is a risk of
thunderstorm in the area. |
| Some random data samples may be lost during the verifier test. This does not indicate that sensor or instrument is faulty. |
| The verifier cannot be used to test the
accuracy of wind direction measurement. During zero wind calibration, the wind direction
data is missing. This does not indicate that the sensor is faulty. |
| Disable heating before performing the verifier test. |