2.5 Precautions for Measurement
2.5.1 Air Velocity Measurement Precautions
Probe has its own directivity characteristics. Make sure that the wind
direction mark is facing against the airflow. (For details on the directivity
characteristics, refer to “12 Probe Directivity” in page 36.) If you are not sure
of the wind direction, slowly rotate the probe and make a measurement at the
point where you get the maximum air velocity reading.
The probe uses the air velocity sensor with the temperature compensation
sensor to compensate air velocity change caused by temperature change. In
order to obtain this compensation effect, both of the sensors must be evenly
exposed to the airflow under the same temperature condition.
For measurement in the environment with rapid temperature change, you
must wait for the reading to become stable after measuring for 20 seconds or
longer.
2.5.2 Air Temperature Measurement Precautions
The response time for temperature measurement improves as the air velocity becomes faster. When the air
velocity is 1m/s, the response time is approximately 30 seconds. Wait for the reading to become stable before
taking the data.
When a measurement is performed in a no-airflow condition, the air temperature reading may become higher
than the actual due to the heat generated by the air velocity sensor. It is recommended that the measurement
is performed in an environment with at least 0.1m/s airflow to obtain accurate reading.
2.5.3 Pressure Measurement Precautions
Only the model 6115 has the pressure measurement function. If you are using the model 6113 or 6114, you
can add this function as an optional extra.
Do not apply pressure of more than 75kPa to the pressure sensor. Excess pressure may cause serious damage
to the sensor.
The operating temperature is 5-40
℃
, when measuring pressure. The instrument may not operate properly
outside this temperature range.
Be sure to perform a zero adjustment before measuring pressure. When performing a zero adjustment, leave
both pressure ports, (+) and (-), open.
2. Getting Started
9
Wind
Wind Direction Mark
