Anemometer, how to use these methods you need to know
the use of the anemometer
1. Anemometer before use to observe whether electric meter pointer refers to zero, if there are any deviation, mechanical adjustment screws can be gently adjusted the meters, return pointer to zero;
2。 Put wind meter calibration switch in the location of the broken
3. Rod will plug in the socket, rod vertical placed, plug pressure probe seal, calibration switch in full position, slowly adjust the full adjustment knobs, make the electric meter pointer refers to the full;
4。 Put calibration switch at zero, slowly adjust the coarse and fine tuning two knobs, make electric meter pointer to point to in the location of the zero
5. After the above steps, gently pull the plug, the rod probe show ( The length can be according to the need to choose) And the probe on the red dot face toward the direction of the wind, according to the degree of meter reading, consult the calibration curve, can be found to be measured wind speed;
6。 After the determination of a number of points ( About 10 min) , you must repeat the above steps 3 and 4, make the current to get inside the instrument standardization
7. Measurement, correction switch should be placed on the location of the broken.
anemometer velocity signal into electrical signal a speed measuring instrument, also can measure fluid temperature or density. Its principle is that the thin wire of a electric heat ( Call hotline) Put in air, hot line heat dissipating capacity is related to flow velocity in the air, and hotline temperature change caused by the resistance resulting from heat dissipating capacity of the velocity signal is transformed into electrical signals. It has two working modes:
1) constant flow. Through hotline current remain unchanged, the temperature change, the hotline resistance to change, and both ends of the voltage changes, the measured velocity;
(2) the thermostat. Hotline temperature remains constant, such as 150 ℃, applying current can be measured according to the required flow rate. Thermostat than constant flow application more widely. Line length is in commonly 0. 5 ~ 2 mm range, range from 1 to 10 microns in diameter, material for platinum, tungsten and platinum rhodium.
if with a very thin ( The thickness is less than 0. 1 micron) Metal film instead of metal wire, is the hot film anemometer, function and hot wire are similar, but more for measuring the liquid flow rate. Hotline in addition to the ordinary single type, also can be a combination of double wire or 3 line, used to measure velocity component in all directions.
from the hotline output electric signal, after amplification, compensation, and digital input computer, can improve the accuracy of measurement, automatic data processing process, expanding speed function, such as the completion of instantaneous value and at the same time average, speed and velocity, turbulence and other turbulence parameters measurement. Hot wire anemometer, compared with pitot probe small volume, little interference flow field; Fast response, to measure the unsteady flow speed; To measure very low speed ( Such as low as zero. 3 m/s) Wait for an advantage.