The radar device then determines the target speed from the difference between the transmitted and reflected signal. FIG. This is a two-axis accelerometer that is suitable for measuring static acceleration (e.g. Calculate Velocity Of Air In The Duct (Specific Gravity Of Oil= 0.7 And, Density Of Water Is 1000 Kg/m3) Provides remote control and operation of float mounted ADCP/ADPs used for gauging rivers. 4.24) consists of a float suitably connected to a recording device. When the antenna transmits the beam of radio waves, the beam forms an elliptical pattern onto the target area. The law of electromagnetic induction is also utilized, which takes the water flow as a conductor to measure the flow velocity. The true speed can be calculated from the indicated speed, using the following formula: If we assume the angle A is 10°, the cosine of A is 0.9848. Thus, the speed calculation must compensate for the horizontal angle. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and scope of the appended claims. A Pitot tube is a device use to measure the fluid flow velocity. DECATUR ELECTRONICS, INC., ILLINOIS, Free format text: A processor in the radar device calculates the cosine correction factor that is applied to the measured velocity of the target point. This Device Is Connected To A U-Tube Manometer With Oil As Manometric Fluid. Current meter measures the velocity of flowing water in an open channel or ditch and streams where direct methods of measurement are not practicable. How do land use activities potentially influence water flows? With the mobile measuring device RP-30 (Radar Profiler) a surface velocity profile from rivers and channels is created and together with the data of the river cross-section and water level the discharge is determined. The wetted primary device restricts the liquid flow stream. It has a tail fin, to allow cable gauging, so can't operate in water as shallow as the Pygmy. They measure water level and convert this to water flow. x-axis and y-axis). This is a useful pr… Another advantage of taking measurements above the water is that waterproof instruments are not required. Open channel flowmeters perform flow measurement of liquids that are open to the atmosphere at some point in the flow measurement path. 1 is a side elevation view of the inventive radar gun tilted down at a 45° angle. The change in … Radar device for measuring water surface velocity, Application filed by Decatur Electronics Inc. In the past, entry of the vertical angle was estimated by the operator and calculated manually or the information was manually entered into the radar device and the software would calculate the cosine correction factor. ADCP Channelmaster - RDI This Acoustic Doppler Current Profiler (ADCP) can accurately measure the velocity of rivers, streams, estuaries, channels, ports and harbours, across a channel up to 300 meters wide. The velocity-measuring device (1) consists of a base unit (10) with a command-display unit (17). Next, here are presented the Top 7 Liquid Flow Measuring Devices for Oil and Natural Gas. This is known as the Doppler effect. Unlike the acoustic doppler devices and POEM, propellor current meters can't measure turbulence. Its smooth towing speed gives superior results to hand towing. The average time on can vary from 0 to 100 percent. Radar has been used for years to determine the speed of moving objects. primary radar systems; Analogous systems, Systems of measurement based on relative movement of target, Velocity or trajectory determination systems; Sense-of-movement determination systems, Velocity or trajectory determination systems; Sense-of-movement determination systems processing the video signal in order to evaluate or display the velocity value, ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SMITH, KIMBLE J.;JANSON, SCOTT D.;SMITH, KEVIN T.;REEL/FRAME:012183/0456;SIGNING DATES FROM 20010909 TO 20010911, ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION, Simulating a radar signal reflected from a moving target, Method and Apparatus for Acquiring Local Position and Overlaying Information, Radar speed measuring device and method based on angle compensation, Device for measuring the frequency of vibrations on a tight drive belt, and method for performing the vibration frequency measurement, Method for estimating flow by means of radar wave flow meter, The device measured for the frequency of vibration of driving belt being tensioned and for performing the method that frequency of vibration is measured, Device for measuring the frequency of vibration in a tensioned drive belt and method for performing vibration frequency measurement, Device for measuring the frequency of vibrations on a tight drive belt and a method for carrying out the vibration frequency measurement, Gyro sensor module and angular velocity detection method, Method and system for determining position and orientation of an object, Surveying and position measuring instrument with a fan-shapped light beam, Level, angle and distance measuring device, Monitor device that measures and displays the flight characteristics of sports objects, Yield monitoring apparatus, systems, and methods, Laser sensor capable of measuring distance, velocity, and acceleration, Low cost 2D position measurement system and method, Solid state orientation sensor with 360 degree measurement capability, System for determining performance characteristics of a golf swing, Handheld optical distance measurement device, Handheld laser light detector with height correction, using a GPS receiver to provide two-dimensional position data, System, method, device and computer code product for improving the readability of an electronic compass, Gradient sensor and method of using the same, Remote attitude and position indicating system, Method and apparatus to determine the wind speed and direction experienced by a wind turbine, Method of adjusting monitor axis of optical sensors, Golfer's wind indicator and club selection assistance device, Method and apparatus to determine object striking instrument movement conditions, System for using a 2-axis magnetic sensor for a 3-axis compass solution, Information on status: application discontinuation. 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. Pitch angle=asin (0.9636)=74.5° or 90°−74.5°=15.5° down. Flow Stations - These are usually a permanent structure located at a carefully selected, or constructed, stable site. The Coriolis Flow Meter point velocity probe (PVP) to investigate groundwater velocity below the water table suggested that the PVP may also be capable of measuring groundwater velocity within the capillary fringe. It is an object of the invention to provide a radar gun that measures surface velocity and automatically compensates for the vertical or tilt angle of the gun with respect to the target. The head is a function of flow velocity, and therefore, the flow rate through the device. All rights reservedPrivacy Policy, 2016, Free phone within New Zealand: 0800 RING NIWA (0800 746 464) Contact details, Air quality monitoring with low-cost sensors, ICES Expert Working Group Meetings – April 2017, Neon Remote Terminal (NRT Terrestrial) - Unidata, Small prop current meters - Ott, Oss, Seba, CHES - smarter use of New Zealand's river waters, NIWA research vessel returns home after epic voyage, Fresh scientific scrutiny for Arrowtown air, Shining new light on ground water measurements, Meeting the flood challenge in post-quake Christchurch. By placing the accelerometer in the radar gun. This also means that the flow rate in the pipe is the same at any location along the length of the pipe. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified, Systems using reflection of radio waves, e.g. 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. A sound velocity probe is a device that is used for measuring the speed of sound, specifically in the water column, for oceanographic and hydrographic research purposes. 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. 2. This ultrasonic Doppler instrument is a compact, easy to use system for measuring water flow in rivers, channels and pipes. It is advantageous to be able to take the velocity measurements above the water surface so that waterproof instruments are not required. When taking readings of moving water, such as rivers or streams, the radar gun is generally positioned above the stream, on a bridge, or adjacent to the stream, on a riverbank. 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. 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. Pitch angle=asin (acceleration in the x direction/1 g calibration from the x sensor reading). ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION. Currently, pan evaporimeters – resembling large pans that are filled with water – are the most commonly used devices to measure evaporation rates. the processor calculating the tilt angle of the radar gun with respect to a horizontal plane. 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. At 90° the target speed is 0 which is grossly incorrect. 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. As the angle increases, the target speed erroneously decreases, as Table 1 below shows. We offer the Global Water Flow Probe. A pitot tube is a simple device meant for measuring the velocity of a liquid at any point. If the indicated speed on the radar gun is 10 feet per second and no cosine correction is made, then the actual speed of the water is 11.17 feet per second. In this manner, the sensor can relay data to a microprocessor. These large propeller type meters are supplied with one propeller for flows up to 6.0 m/s. Basically, the current meter is a wheel having several cups or vanes which turn round due to the force of water current. While technology has changed over the years, we've still achieved a high level of standardization. 02062 under model number ADXL202. Each sensor has a frequency output from which its angle position is determined. Thus pitch angle=asin (53/55). 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 … It is primarily used in measuring discharge. Propellor current meters - these are the older mechanical meters and still the standard in New Zealand. The x and y-axis sensors generate a PWM signal internally to the accelerometer, The sensor is designed to provide a 50% duty cycle signal when it is sensing 0 g (where g is the unit of measurement of the earth's gravitational pull). The size of the elliptical pattern depends on the distance between the antenna and the target. 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) . Doppler meters measure the frequency of sounds that are bounced back from a moving object. The radar device includes a tilt sensor, or accelerometer, to measure the angle of tilt of the radar device with respect to a target point located at a distance from the radar device. Copyright, NIWA. The outputs are duty cycle modulated (DCM) signals whose duty cycles (ratio of pulse-width to period) are proportional to the acceleration in each of the two axes (i.e. 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 discharge through weirs and flumes is a function of water level, so water level measurement techniques must be used. “The device is a more efficient and inexpensive way to measure evaporation when compared with existing methods,” Bengaluru-based IISc said in a statement on Friday. This results in an automatically corrected measured velocity being displayed on the radar device. 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. This Acoustic Doppler Current Profiler (ADCP) can accurately measure the velocity of rivers, streams, estuaries, channels, ports and harbours, across a channel up to 300 meters wide. 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. When This Pitot Static Tube Is Placed In The Flow, 50mm Difference In Manometric Fluid Is Noted. The device contains an accelerometer that has two sensors. POEM is a Pressure Operated Electronic Meter, with no moving parts, developed for gauging flooded rivers with flow rates up to 10 m/sec. 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. 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. When a vertical (pitch-down) angle is introduced into the measurement, both angles affect the final calculated display speed. Swoffer water flow equipment has the advantage of easy to use, flexible design to measure shallow and deep channels as well as low and rapid velocities. Swoffer water flow meters are designed to measure velocity in any application from streams and rivers to storm water and sewage. Electromagnetic meters. The fluctuations in the water level make the float move which in turn actuates a pen. The sensors are aligned horizontally with the two sides of the radar gun and separated by 90°. In both cases, an especial measuring device is employed to measure the water or the fracturing fluid that is pumped into the rock. The Pitot tube was invented by a french engineer Henri Pitot i early 18s and further modified by a french scientist Henry Darcy. a radar gun with means for generating a signal at a predetermined frequency directed at an object, the radar gun oriented at a vertical angle with respect to the object. There are several types of open channel flow meters, the traditional methods using primary devices such as flumes or weirs. ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SMITH, KIMBLE J.;JANSON, SCOTT D.;SMITH, KEVIN T.;REEL/FRAME:012183/0456;SIGNING DATES FROM 20010909 TO 20010911, Free format text: FIG. The equation is used to measure flow in locations where the construction of a hydraulic structure (flume or weir) is impractical. 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. The accelerometer, A PWM circuit makes a square wave with a variable on-to-off ratio. Global Water Flow Probes are highly accurate water velocity instruments for measuring flow in open channels and partially filled pipes. While the invention has been described in conjunction with a specific embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Instead, it must be calculated in a process known as stream gaging. Most have two or three different propellors to extend the range from low to higher flows. It is not the most practical way to measure the velocity, but that is not … Accelerometers can detect a change in tilt because they can measure and account for the Earth's gravity. Honestly, most people who gauge streams, including the USGS don't continuously measure velocity at all. Not all flow measuring devices ... wood, or fiberglass and can measure water over a wide variety of flow ranges. The accelerometer generates a signal representing the tilt angle. The radar device has a microprocessor that computes the velocity based upon the Doppler shift. 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. Such a device (Fig. water to back up, creating a head behind the barrier. Assignors: SMITH, KEVIN T., JANSON, SCOTT D., SMITH, KIMBLE J. Simply recording water depth does not provide a reliable measure of water flow, for example, depth may vary while flow remains constant. This internal automatic compensation allows for accurate measurement of the surface velocity of the water. Thus there has been provided a surface velocity radar gun with automatic cosine correction for measuring water velocity at an angle that fully satisfies the objects set forth above. a tilt sensor mounted in the radar gun to provide an output signal that includes a tilt angle component. Read about how a POEM was used to gauge the flow of water entering the Lake Pukaki canal on the Waitaki hydroelectric scheme  POEM has no moving parts and, in addition to measuring flow up to 10m/s, can simultaneously provide useful information about turbulence. This invention relates to measuring devices and more particularly to a surface velocity radar device for measuring water surface velocity. The Flow Probe incorporates the unique Turbo-Prop propeller sensor, which uses the most accurate positive displacement technique available for velocity … Streamflow is a measurement of the amount of water flowing through a stream or river over a fixed period of time. “The device is a more efficient and inexpensive way to measure evaporation when compared with existing methods,” Bengaluru-based IISc said in a statement on Friday. The greater the tilt angle, the greater the effect of gravity on one of the sensors. The conversion is usually done with a rating derived from gauging the cross section of the open channel beside the station, or using the relationship associated with a weir constructed downstream. 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. 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. 7.72). 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. Pygmy meter: a wheel is rotated by water flow and the rate of the rotation signifies the water velocity. 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