Impeller Anemometer - What is the function of the anemometer?
Determination of wind speed Commonly used instruments are cup anemometers, wing anemometers, cartesian thermometers and hot bulb anemometers. Wing and cup anemometers are easy to use, but their inertia and mechanical friction resistance are high, and they are only suitable for the determination of large wind speeds. Hot ball type electric anemometer
1. construction principle is a kind of instrument that can measure the low wind speed, and its measurement range is 0.05-10m/s. It is composed of two parts, namely, hot ball type measuring rod probe and measuring instrument. Probe has a diameter of 0.6mm glass ball, the ball is wound with heating glass ball with nickel-chromium wire ring and two series-connected thermocouples. The cold end of the thermocouples is connected to a phosphor bronze strut, which is directly exposed to the airflow. When a current of a certain size is passed through the heating coil, the temperature of the glass sphere rises. The degree of increase is related to the wind speed, when the wind speed is small, the degree of increase is large; on the contrary, the degree of increase is small. The magnitude of the increase is indicated by the thermocouple on the meter. According to the meter reading, check the calibration curve, you can find out the wind speed (m/s).
2. Usage
① Observe whether the pointer of the meter is pointing to zero point before use, if it is offset, gently adjust the mechanical adjustment screw of the meter to make the pointer return to zero point;
② Place the calibration switch in the off position;
③ Plug the measuring rod into the socket, place the measuring rod vertically upward, press the screw plug tightly to make the probe sealed, the "correction switch" is placed in the fullness position, and slowly adjust the "fullness adjustment" knob, so that the meter pointer points to the fullness position;
④Place the "calibration switch" at "zero position", slowly adjust the two knobs of "coarse adjustment" and "fine adjustment" to make the meter pointer point at the zero position. Adjust the "coarse adjustment" and "fine adjustment" knobs slowly so that the meter pointer is at the zero position;
⑤ After the above steps, gently pull the screw plug to expose the probe of the measuring rod (the length can be selected according to the need), and make the red dot on the probe face to face with the wind direction, according to the meter reading, check the calibration curve, you can find out the measured wind speed;
(6) In the determination of a number of minutes later (10min or so), must repeat the above ③, ④ steps once, so that the current in the meter to be standardized;
(7) After the measurement, the "calibration switch" should be placed in the position of the broken.
3. Precautions
① This instrument is a more precise instrument, strictly guard against collision and vibration, can not be used in excessive dust or corrosive places.
② The instrument is equipped with 4 batteries, divided into two groups of three in series, a group is a single section. In adjusting the "fullness adjustment" knob, if the meter can not reach the full scale, indicating that a single battery has been depleted; in adjusting the "coarse", "fine tuning" knob, if the meter gauge When adjusting the "coarse adjustment" and "fine adjustment" knobs, if the meter pointer cannot return to zero, it means that the three batteries have been exhausted; when replacing the batteries, open the small door at the bottom of the instrument and connect it in the correct direction. The batteries should be replaced by opening the small door at the bottom of the instrument and connecting them in the right direction.
③After the instrument is repaired, it must be recalibrated.
