A rain gauge is an instrument used by meteorologists and hydrologists to measure precipitation in an area over time. With the development of science and technology, China's atmospheric monitoring automation system continues to advance, and the rainfall recorder has been put into business use. Rain gauges are automatic observation instruments with high technological content. Sensors are all electrical signals. Therefore, the measurement accuracy changes with time. Using a rain gauge when the wind is too heavy (tropical storm or hurricane) is meaningless because the recorded result will be too much error while causing damage to the gauge itself. In addition, rainwater adheres to the wall or funnel, which can result in slightly smaller measurements. When the temperature is close to the freezing point, the rain may freeze when it falls on the rain gauge, causing hopper clogging or other problems. Therefore, in order to transmit accurate, reliable, and uniform values, the rainfall recorder must be calibrated and calibrated regularly to make it comparable. Rain recorder field calibration method: Precision Bevel Gears,Industrial Robot Spiral Bevel Gear,Helical Spiral Bevel Gear,Spiral Bevel Gears Jiangsu Juli Gear Co., Ltd. , https://www.spiral-bevelgear.com
1. Standards and equipment for on-site calibration of rainfall recorders: 0-250L vernier caliper with minimum division value not greater than 0.05L; 157.08ml (equivalent to 10L precipitation) standard ball; level gauge; stopwatch, etc.
2. The calibration point selection was performed on 10mm rainfall.
3. Water purifier mouth to be level, with a horizontal ruler to measure in different directions; with a vernier caliper to measure the diameter of the rain gauge water inlet is 200 +0.6 mm, the wall of the water retainer and the water inlet should be smooth, the edge must not have trachoma, glitches, Defects and other defects. The sensor of the rain gauge sensor uses ground pulse signals to measure ground rainfall, each pulse is 0.1mm. Before indicating the calibration, check whether the master and collector are normal and whether the parameters are set correctly. The use of latex tubes to connect the standard ball and the control valve cannot cause leakage or leakage. After the time control, the rainfall intensity of 4 mm/min and 1 mm/min was injected into the water intake of the rain gauge, and the rainfall measurement value of the automatic weather station was recorded. Each precipitation intensity was calibrated three times and the average value of the three measurements was subtracted. The standard value (standard value of 10 mm) is used as the measurement error of the precipitation intensity. 10mm rainfall error ≤ 0.4mm. The maximum of two precipitation intensity measurement errors is used as the calibration result of the automatic weather station rain gauge sensor, which can be calibrated on site at least once a year according to the local rainfall intensity.