A variety of test methods for the digital anemometer
Digital anemometer tests include average wind speed test and turbulence component test (wind turbulence 1~150KHz, different from fluctuation). Methods for testing average wind speed include thermal, ultrasonic, impeller, and drag tube types, etc.
This method is to test the resistance change produced when the sensor is cooled by the wind when it is powered on, thereby testing the wind speed. No information about wind direction can be obtained. In addition to being easy to carry and convenient, it has a high cost-performance ratio and is widely used as a standard product of anemometers. Thermal anemometers use platinum wire, thermocouples, or semiconductor elements, but our company uses platinum coiled wire. The material of platinum wire is the most stable materially. Therefore, it has advantages in terms of long-term stability and temperature compensation.
The wind direction sensor of the photoelectric anemometer uses a low-inertia light metal wind vane to respond to the wind direction and drive the coaxial code disk to rotate. This code disk is encoded in Gray code and scanned with photoelectrons to output an electrical signal corresponding to the wind direction.
The photoelectric wind speed sensor uses a low-inertia wind cup, which rotates with the wind to drive the coaxial optical disc to rotate. It uses photoelectronic scanning to output a pulse train and output a pulse frequency corresponding value corresponding to the number of revolutions, which is convenient for collection and processing. High strength, good starting, and in line with national meteorological measurement standards;
The wind direction sensor has a built-in electronic compass and automatically locates the direction angle. It can be installed in a fixed place or in a mobile place (such as special vehicles, ships, drilling platforms, etc.)
Rotary probe for anemometer
The working principle of the rotary probe of the digital anemometer is based on converting the rotation into an electrical signal. First, through a proximity induction start, the rotation of the rotor is "counted" and a pulse series is generated, which is then converted and processed by the detector, that is The speed value can be obtained. The large-diameter probe (60mm, 100mm) of the anemometer is suitable for measuring turbulent flows with medium and small flow rates (such as at the pipe outlet). The small-diameter probe of the anemometer is more suitable for measuring airflow where the cross-section of the pipe is more than 100 times larger than the cross-sectional area of the exploration head.
Positioning of digital anemometer in air flow
The correct adjustment position of the anemometer's wheel probe is when the air flow direction is parallel to the wheel axis. When the probe is gently rotated in the air flow, the indication value will change accordingly. When the reading reaches the maximum value, the probe is in the correct measuring position. When measuring in a pipeline, the distance from the starting point of the straight part of the pipeline to the measurement point should be greater than 0XD. The impact of turbulent flow on the thermal probe and pitot tube of the anemometer is relatively small.
Digital anemometer measures air flow velocity in pipes
Practice has proven that the 16mm probe of the anemometer is the most versatile. Its size not only ensures good permeability, but also can withstand flow rates up to 60m/s. As one of the feasible measurement methods, air flow velocity measurement in pipelines, indirect measurement procedures (grid measurement method) are suitable for air measurement.
