The only thing that is necessary are Arduino and some basic crafting skills and, of course, a free flowing stream. When the target's path (the water flow direction) is not parallel with the gun's antenna, the radar device displays a speed which is lower than the actual water surface velocity. Next, here are presented the Top 7 Liquid Flow Measuring Devices for Oil and Natural Gas. It is primarily used in measuring discharge. Copyright, NIWA. The velocity-measuring device (1) consists of a base unit (10) with a command-display unit (17). The head is a function of flow velocity, and therefore, the flow rate through the device. The accelerometer, A PWM circuit makes a square wave with a variable on-to-off ratio. x-axis and y-axis). The radar device has a microprocessor that computes the velocity based upon the Doppler shift. Instead, it must be calculated in a process known as stream gaging. Radar device for measuring water surface velocity, Application filed by Decatur Electronics Inc. Basically, the current meter is a wheel having several cups or vanes which turn round due to the force of water current. Thus it is important to correct for the vertical angle when taking measurements of surface water from an elevated position. The Flow Probe incorporates the unique Turbo-Prop propeller sensor, which uses the most accurate positive displacement technique available for velocity … This velocity measuring device is a useful tool for manually measuring flow in open channel applications. By placing the accelerometer in the radar gun. The proposed velocity-measuring device (1) can measure the velocity of a wide range of objects via simple sound waves utilising the Doppler-effect principle. At the same time that the microprocessor is receiving a reading from the y-axis sensor, Turning to FIG. Accelerometers can detect a change in tilt because they can measure and account for the Earth's gravity. Its smooth towing speed gives superior results to hand towing. Global Water Flow Probes are highly accurate water velocity instruments for measuring flow in open channels and partially filled pipes. This Acoustic Doppler (water) Current Profiler (ADCP) can measure water velocity and discharge in shallow streams, ranging from 15 to 200 cm deep, in minutes. The inventive device is a radar gun that measures and reports surface velocities. Manning’s Equation, as it is commonly referred to in the United States, is an empirically derived formula for estimating the average velocity of a liquid flowing in an open channel. These small propeller type meters are supplied with two propellers, one for very low flows (up to 0.3 m/s) and another for higher flows (up to 2.0 m/s) . NIWA has built flow stations on rivers and canals for decades. Often the device is used in hazardous conditions, such as flooding, so using the radar device above the water minimizes the risk to the operator. This is a phenomenon called the cosine effect. Simultaneously the other sensor displaces a smaller angle and the effect of gravity on the other sensor is less. Each sensor has a frequency output from which its angle position is determined. This internal automatic compensation allows for accurate measurement of the surface velocity of the water. Mobile measuring system for non-contact discharge measurement. A radar device for measuring the surface velocity of water moving in a horizontal plane in which the radar device is positioned above or below the horizontal plane. An accelerometer that is found to satisfactorily operate is one manufactured by Analog Devices, Inc. One Technology Way, Norwood, Mass. The wetted primary device restricts the liquid flow stream. In all cases, the radar device is elevated above the water, so the vertical angle must be compensated for. With this device you are able to measure the velocity of a free flowing stream. A pitot tube is a simple device meant for measuring the velocity of a liquid at any point. This invention relates to measuring devices and more particularly to a surface velocity radar device for measuring water surface velocity. Many factors can generate currents, such as gravitational forces, rotation of the earth, wind, water conditions gradients and/or geographical landscapes. ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION. It has a tail fin, to allow cable gauging, so can't operate in water as shallow as the Pygmy. Most have two or three different propellors to extend the range from low to higher flows. The reflected signal frequency shifts by an amount proportional to the speed of the target. A radar gun transmits and directs a signal or beam of microwave energy (radio waves) having a given frequency at an approaching or receding target. DECATUR ELECTRONICS, INC., ILLINOIS, Free format text: Staff gages and float-operated units are the simplest devices used for this purpose. It is advantageous to be able to take the velocity measurements above the water surface so that waterproof instruments are not required. They measure water level and convert this to water flow. This Device Is Connected To A U-Tube Manometer With Oil As Manometric Fluid. At 90° the target speed is 0 which is grossly incorrect. The equation is used to measure flow in locations where the construction of a hydraulic structure (flume or weir) is impractical. means for correcting the velocity measured to correct for the radar gun being disposed above or below the horizontal thus resulting in an erroneous reading due to the radar gun being disposed at an angle with respect to the horizontal, the means for correcting the velocity measured being a sensor that senses the angle of the radar gun with respect to the horizontal. The radar gun is thus positioned at a vertical angle with respect to the water surface. These have been used to gauge rivers for decades, and despite being mechanical, are reasonably robust and reliable but, unlike the ADCP, need to be calibrated annually. There are many different types of meters by the most common is the Pygmy meter, the vortex meter, the flow probe, and the current meter: They are briefly described below. Magnetic flow meters, commonly referred to as "mag meters", are technically a velocity-type water meter, except that they use electromagnetic properties to determine the water flow velocity, rather than the mechanical means used by jet and turbine meters. When the operator tilts the radar gun at an upward or downward angle from the horizontal level position, the effect of gravity displaces the sensor. Owner name: The speed of the rotating wheel indi­cates the velocity of the current. This is known as the Doppler effect. 3 is an electrical schematic diagram of the accelerometer used to determine tilt angle and how it is connected to the radar device's microprocessor. This small bucket wheel current meter has a very low starting velocity and no tail fin, so is ideal for measuring very low flows in shallow water. Not all flow measuring devices ... wood, or fiberglass and can measure water over a wide variety of flow ranges. Others are more suitable for monitoring water flow in pipes. The sensors are aligned horizontally with the two sides of the radar gun and separated by 90°. The radar gun reads the frequency data from the tilt sensors, and the computer software uses this in calculating the cosine corrected angle of the angle formed by the radar device and the point where the velocity is measured. The electromagnetic flowmeter is capable of measuring flow rates in different water quality conditions, which brings small disturbances to the water flow, and can measure instantaneous flow rates, but the method is susceptible to interference from nearby electromagnetic … Open channel flowmeters perform flow measurement of liquids that are open to the atmosphere at some point in the flow measurement path. a processor mounted in the radar gun to receive the output signal. Thus, the speed calculation must compensate for the horizontal angle. A processor in the radar device calculates the cosine correction factor that is applied to the measured velocity of the target point. The water velocity probe consists of a protected water turbo prop positive displacement sensor coupled to an expandable probe handle with a digital readout display. The above Table 1 shows the actual velocity speeds in the left column and the displayed speed at antenna to target angles in the right column if the radar gun is not adjusted for the horizontal angle from the position of the gun antenna to the target. The device contains an accelerometer that has two sensors. Honestly, most people who gauge streams, including the USGS don't continuously measure velocity at all. Applicant's invention provides for automatically entering the vertical or tilt angle into the software for the vertical cosine correction, replacing the operator's manual entry of the past. In this manner, the sensor can relay data to a microprocessor. Pitch angle=asin (acceleration in the x direction/1 g calibration from the x sensor reading). RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES, Systems using the reflection or reradiation of radio waves, e.g. 1 there is illustrated a radar gun. For water flowing in a pipe under steady-state conditions (i.e., not changing over time), continuitymeans the water that flows into one end of a pipe must flow out of the other end. Currently, pan evaporimeters – resembling large pans that are filled with water – are the most commonly used devices to measure evaporation rates. When the beam strikes the target, a small amount of energy from the beam is reflected back to the antenna in the radar device. Meters are devices that measure the stream flow by directly measuring the current. The continuity equation can be represented as: Flow = velocity * area The notion of continuity under steady state conditions results in the product of the velocity * area being equal to a constant at any location along the pipe. This is a useful pr… When used in measuring the volume of water passing though the water in a water meter, or the speed of the water passing through a flow meter, it is actually measuring the sound as it bounces off of bubbles, dirt or impurities in the water. The law of electromagnetic induction is also utilized, which takes the water flow as a conductor to measure the flow velocity. These consist of a primary device, transducer, and flow transmitter. It is a related object to provide a radar gun with automatic tilt or vertical angle correction so that the gun can be positioned above the water surface, minimizing the hazardous risks to the operator if the operator was required to stand in the moving water. The liquid may be entirely open to the atmosphere, or may be contained within a closed pipe that is not full of liquid and only open to the atmosphere at the installation point of the flowmeter itself. This also means that the flow rate in the pipe is the same at any location along the length of the pipe. There are also a few less commonly used devices, such as a radar setup that measures the velocity of waves and micro-waves on the surface of the water. The USGS has been doing this since 1889, when it established its first stream gage on the Rio Grande River in New Mexico to determine how much water was availabl… Velocity measurement of water flow is an important task in hydrological monitoring [1–3]. 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