A rain gauge with self-calibration function
By incorporating a weight sensor and an ultrasonic probe into the rain gauge, an online self-calibration function is achieved, solving the measurement error problems caused by temperature and humidity changes and pollutant adhesion, and ensuring the long-term high accuracy and data reliability of the rain gauge.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG RUILIN INFORMATION TECH CO LTD
- Filing Date
- 2025-08-01
- Publication Date
- 2026-05-26
AI Technical Summary
Existing ultrasonic rain gauges suffer from increased measurement errors due to temperature and humidity changes, residual water, and contaminant adhesion. They also lack online calibration methods, have high maintenance costs and long maintenance cycles, and cannot guarantee long-term data reliability.
A rain gauge with self-calibration function was designed. By combining a weight sensor and an ultrasonic probe, it can achieve online self-calibration with zero manual intervention and zero external equipment. Automatic calibration is performed using a calibration tube and a drain valve, and real-time correction is performed in conjunction with a data processing unit.
It achieves high accuracy in long-term liquid level detection, reduces maintenance costs and time, and ensures the data reliability of the rain gauge during long-term operation.
Smart Images
Figure CN224287168U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of rain gauge technology, specifically relating to a rain gauge with self-calibration function. Background Technology
[0002] Existing ultrasonic rain gauges typically consist of a top-opening rain collection tube, an ultrasonic transducer at the bottom of the tube, and a matching data processing unit. Rainwater is collected through a funnel and enters the measuring chamber. The ultrasonic transducer emits sound waves downwards and receives the echoes from the liquid surface. The time of flight is used to calculate the water level in real time, thereby determining the cumulative rainfall. Because this method has no moving mechanical parts, its initial accuracy can reach ±3% to ±5%, and it facilitates remote readings, making it widely used in urban meteorological stations.
[0003] However, after long-term operation, ultrasonic rain gauges still have obvious shortcomings: changes in temperature and humidity cause sound velocity drift, residual water in the cylinder cannot be completely drained, causing zero-point offset, and mud, sand and oil adhering to the transducer or liquid surface form a scattering layer, all of which gradually increase the measurement error; moreover, there is a lack of online calibration methods, and calibration can only be carried out manually on-site with standard measuring tools on a regular basis, which results in long maintenance cycles, high costs, and difficulty in ensuring long-term data reliability. Utility Model Content
[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution.
[0005] A rain gauge with self-calibration function includes a cylindrical body with an open top. A funnel is provided inside the cylinder, dividing the inner cavity of the cylinder from top to bottom into a water collection chamber and a measuring chamber. An ultrasonic probe for detecting water level is installed in the measuring chamber. The cylinder body is supported by a mounting bracket, on which a weight sensor for weighing the cylinder is mounted. A calibration pipe and a calibration valve are provided on one side of the measuring chamber, and a drain pipe and a drain valve are provided at the bottom of the measuring chamber. The weight sensor, ultrasonic probe, calibration valve, and drain valve are all electrically connected to a data processing unit.
[0006] In a preferred embodiment, the funnel opening is close to one side of the inner wall of the measuring cavity, and the ultrasonic probe is close to the opposite side of the inner wall.
[0007] In a preferred embodiment, the leak is connected to a water inlet pipe, and the outlet of the water inlet pipe is located near the bottom of the measuring chamber.
[0008] In a preferred embodiment, the outlet of the water inlet pipe faces the inner wall of the measuring chamber so that the outflowing rainwater flows down the inner wall.
[0009] In a preferred embodiment, the water inlet pipe includes an upper pipe, a tee connector, and a lower pipe connected in sequence; the third end of the tee connector is connected to the correction pipe.
[0010] In a preferred embodiment, an inlet valve is installed at the upper pipe.
[0011] In a preferred embodiment, the bottom of the measuring chamber is shaped like an inverted frustum, and the drain pipe is located at the center of the bottom.
[0012] Compared with the prior art, this application has the following beneficial technical effects: it has a self-calibration function, which can realize online self-calibration with zero manual intervention and zero external equipment, so as to maintain the accuracy of liquid level detection over a long period of time. Attached Figure Description
[0013] Figure 1 This is a 3D view of a rain gauge.
[0014] Figure 2 This is a top view of the rain gauge.
[0015] Figure 3 for Figure 2 Sectional view at point AA.
[0016] Figure 4 This is an assembly drawing of the rain gauge section.
[0017] The following is an explanation of the reference numerals in the attached figures:
[0018] 100. Cylinder; 101. Water collecting chamber; 102. Measuring chamber; 110. Funnel; 111. Leakage outlet; 120. Ultrasonic probe; 130. Mounting bracket; 131. Weight sensor; 140. Calibration pipe; 141. Calibration valve; 150. Drain pipe; 151. Drain valve; 160. Inlet pipe; 161. Upper pipe; 162. T-connector; 163. Lower pipe; 164. Inlet valve; 165. Outlet; 170. Data processing unit. Detailed Implementation
[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0020] In the following embodiments, the same or similar reference numerals denote the same or similar components or components with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0021] In the description of this utility model, it should be understood that the terms such as center, longitudinal, transverse, length, width, thickness, upper, lower, front, back, left, right, vertical, horizontal, top, bottom, inner, outer, clockwise, and counterclockwise, indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description; therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features shown. In the description of this utility model, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," etc., should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0022] Reference Figures 1 to 4 A rain gauge with self-calibration function includes a cylindrical body 100 with an open top. A funnel 110 is provided inside the cylindrical body 100, dividing the inner cavity of the cylindrical body 100 from top to bottom into a water collection chamber 101 and a measuring chamber 102. An ultrasonic probe 120 for detecting water level is provided in the measuring chamber 102. The cylindrical body 100 is supported by a mounting bracket 130, on which a weight sensor 131 for weighing the cylindrical body 100 is mounted. A calibration pipe 140 and a calibration valve 141 are provided on one side of the measuring chamber 102, and a drain pipe 150 and a drain valve 151 are provided at the bottom of the measuring chamber 102. The bottom of the measuring chamber 102 is shaped like an inverted frustum, with the drain pipe 150 located at the center of the bottom. The weight sensor 131, ultrasonic probe 120, calibration valve 141, and drain valve 151 are all electrically connected to a data processing unit 170.
[0023] To reduce interference from water turbulence and fluctuations on the measurement, the outlet 111 of the funnel 110 is located near one side of the inner wall of the measuring cavity 102, and the ultrasonic probe 120 is located near the opposite inner wall. The outlet 111 is connected to a water inlet pipe 160, and the outlet 165 of the water inlet pipe 160 is located near the bottom of the measuring cavity 102. The outlet 165 of the water inlet pipe 160 faces the inner wall of the measuring cavity 102, allowing rainwater to flow down the inner wall. This design keeps the water flow away from the ultrasonic probe, eliminating turbulence and bubble interference in the probe area, ensuring stable echoes during the calibration phase, and improving the accuracy of the reference data. Rainwater is directly guided to the bottom of the measuring cavity 102 through the water inlet pipe 160. When the water level exceeds the outlet 165, the water flows upwards, avoiding splashing that could cause weight measurement errors.
[0024] To improve the detection range of water levels, the inlet pipe 160 includes an upper pipe 161, a tee connector 162, and a lower pipe 163 connected in sequence; the third end of the tee connector 162 is connected to the calibration pipe 140. The tee connector 162 integrates the daily rainwater channel and the calibration channel into the same pipeline, facilitating pipeline maintenance. An inlet valve 164 is installed at the upper pipe 161, which is used in scenarios where the single rainfall exceeds the maximum measurable water level of the measuring chamber 102.
[0025] The working principle of the rain gauge described in this application is as follows:
[0026] Daily rainfall data collection: Rainwater is collected by funnel 110 and flows into measuring chamber 102 through inlet pipe 160. Ultrasonic probe 120 detects water level in real time, and weight sensor 131 records the total weight of cylinder 100 simultaneously; data processing unit 170 cross-validates water level and weight to obtain the water level of this rainfall.
[0027] Handling of excessive water level: When the water level in the measuring chamber 102 reaches the maximum range, the data processing unit 170 immediately closes the inlet valve 164, and the subsequent rainwater is temporarily stored in the collection chamber 101; then the drain valve 151 is opened to empty the measuring chamber 102, and then the drain valve 151 is closed and the inlet valve 164 is reopened, and the system continues the next round of data acquisition to ensure continuous monitoring without interruption.
[0028] Online self-calibration: First, close the inlet valve 164 and open the drain valve 151 to completely empty the measuring chamber 102; then close the drain valve 151 and inject a known volume of clean water into the chamber through the calibration pipe 140. The weight sensor 131 weighs the water in real time and converts it into a standard water level. This standard water level is then compared with the value measured by the ultrasonic probe 120, and the system automatically corrects the probe coefficient to eliminate long-term drift; after calibration, the measuring chamber 102 is emptied again and normal rainfall collection resumes. The system can be set to perform self-calibration periodically or when the cumulative error exceeds a threshold. The entire process requires no manual intervention and is automatically completed by the data processing unit 170, ensuring that the rain gauge maintains high accuracy during long-term operation.
[0029] The scope of protection of this utility model includes, but is not limited to, the above embodiments. The scope of protection of this utility model is defined by the claims. Any substitutions, modifications, or improvements to this technology that are easily conceived by those skilled in the art shall fall within the scope of protection of this utility model.
Claims
1. A rain gauge with self-calibration function, comprising a cylindrical body (100) with an open top, wherein a funnel (110) is provided inside the cylindrical body (100), the funnel (110) dividing the inner cavity of the cylindrical body (100) from top to bottom into a water collection chamber (101) and a measuring chamber (102), wherein an ultrasonic probe (120) for detecting water level is provided in the measuring chamber (102), characterized in that, The cylinder (100) is supported by a mounting bracket (130), on which a weight sensor (131) for weighing the cylinder (100) is mounted; a calibration tube (140) and a calibration valve (141) are provided on one side of the measuring chamber (102), and a drain pipe (150) and a drain valve (151) are provided at the bottom of the measuring chamber (102); the weight sensor (131), the ultrasonic probe (120), the calibration valve (141) and the drain valve (151) are all electrically connected to the data processing unit (170).
2. A rain gauge with self-calibration function according to claim 1, characterized in that, The funnel (110) has its outlet (111) close to the inner wall of the measuring cavity (102) on one side, and the ultrasonic probe (120) is close to the inner wall on the opposite side.
3. A rain gauge with self-calibration function according to claim 2, characterized in that, The leak (111) is connected to a water inlet pipe (160), and the outlet (165) of the water inlet pipe (160) is located near the bottom of the measuring chamber (102).
4. A rain gauge with self-calibration function according to claim 3, characterized in that, The outlet (165) of the inlet pipe (160) faces the inner wall of the measuring chamber (102) so that the rainwater flowing out flows down the inner wall.
5. A rain gauge with self-calibration function according to claim 3, characterized in that, The water inlet pipe (160) includes an upper pipe (161), a tee connector (162), and a lower pipe (163) connected in sequence; the third end of the tee connector (162) is connected to the correction pipe (140).
6. A rain gauge with self-calibration function according to claim 5, characterized in that, A water inlet valve (164) is installed at the upper pipe (161).
7. A rain gauge with self-calibration function according to claim 1, characterized in that, The bottom of the measuring chamber (102) is shaped like an inverted frustum, and the drain pipe (150) is located at the center of the bottom.