What is the function of an anemometer?
The commonly used instruments for measuring wind speed include cup anemometers, wing anemometers, kata thermometers, and hot ball electric anemometers. Wing and cup anemometers are easy to use, but they have high inertia and mechanical friction resistance, making them only suitable for measuring larger wind speeds. Hot ball electric anemometer
1. The construction principle is an instrument that can measure low wind speeds, with a measurement range of 0.05-10m/s. It consists of two parts: a hot ball probe and a measuring instrument. The probe has a glass ball with a diameter of 0.6mm, surrounded by a nickel chromium wire ring for heating the glass ball and two thermocouples in series. The cold end of the thermocouple is connected to a phosphor copper pillar, directly exposed to the airflow. When a certain amount of current passes through the heating coil, the temperature of the glass ball increases. The degree of increase is related to the wind speed, and the degree of increase is greater when the wind speed is small; On the contrary, the degree of increase is small. The magnitude of the increase is indicated on the meter by a thermocouple. Based on the reading of the electricity meter, check the calibration curve to determine the wind speed (m/s).
2. Usage
① Before use, observe whether the pointer of the meter points to zero. If there is any deviation, gently adjust the mechanical adjustment screw of the meter to return the pointer to zero;
② Place the calibration switch in the off position;
③ Insert the plug of the measuring rod into the socket, place the measuring rod vertically upwards, press the plug tightly to seal the probe, place the "calibration switch" in the full degree position, and slowly adjust the "full degree adjustment" knob to make the pointer of the electricity meter point at the full degree position;
④ Place the "calibration switch" in the "zero position" and slowly adjust the "coarse adjustment" and "fine adjustment" buttons to make the meter pointer point at the zero position;
⑤ After the above steps, gently pull the plug to expose the probe of the measuring rod (length can be selected according to needs), and make the red dot on the probe face the opposite wind direction. Based on the reading of the electricity meter, refer to the calibration curve to find the measured wind speed;
⑥ After measuring several points (about 10 minutes), steps ③ and ④ above must be repeated once to standardize the current inside the instrument; ⑦ After the measurement is completed, the "calibration switch" should be placed in the off position.
3. Precautions
① This instrument is a relatively precise instrument that is strictly protected from collision and vibration. It should not be used in places with excessive dust content or corrosive properties.
② The instrument is equipped with four batteries, which are divided into two groups: one group is connected in series with three batteries, and the other group is a single battery. When adjusting the "full scale adjustment" knob, if the meter cannot reach full scale, it indicates that a single battery has been exhausted; When adjusting the "coarse adjustment" and "fine adjustment" buttons, if the meter pointer cannot return to zero, it indicates that the three batteries have been exhausted; When replacing the battery, open the small door at the bottom of the instrument and connect it in the correct direction.
③ After the instrument is repaired, it must be recalibrated.
