KDF1200 Portable Doppler Flow Meter 1mm/s Resolution 7.2V～15V Flow Range 0.02m/s～5.00m/s

1.Introduction

Doppler flow meter principle: When the ultrasonic sound source and the observer move relative to each other, the frequency received by the observer will be different from the frequency of the ultrasonic sound source. Therefore, small particles and small bubbles moving with the water relative to the ultrasonic transducer will also change the transducer receiving frequency, and increase with the increase of the suspended motion speed in the water.The Doppler frequency shift is thus measured, and the flow rate of the water at the point where the Doppler current meter is located is also measured. Multiply it by the cross-sectional area of the channel to get the flow information.

Mainly used in irrigation open channels, municipal sewer pipes, hydrological basins and other occasions. It is particularly suitable for low water level occasions and can work when the water level exceeds 15 cm. In regular pipes and channels, the water depth is measured by the pressure sensor on the flow meter, and the flow rate is measured by the ultrasonic sensor to calculate the flow rate.

Because the Doppler flow rate measurement requires the speed of sound propagation in water, and the speed of sound propagation in water is closely related to the water temperature, a temperature sensor is built in for temperature measurement, and then the sound speed is corrected.

The liquid level depth measurement uses a pressure sensor to measure the distance from the flow sensor to the liquid surface.

The handheld device stores trapezoidal, rectangular, circular and other channel profile models, which can easily calculate the flow rate of common channels.

2.Feature

• Modbus communication protocol is adopted, and RS485 bus is used to communicate with the handheld device.
• The underwater sensor equipment is easy to install. There is a metal base fixing device, which is easy to install.
• The equipment is all electronically designed, with wide voltage power supply, low power consumption, and no mechanical parts. It has the advantages of accurate and stable measurement, high reliability, and strong anti-interference.
• Wide range of applications. It can be used in various water environments from tap water to Yellow River water.
• The shell is made of PVC plastic, which can effectively waterproof and seal
• Internally powered by 12V rechargeable battery

3.Technical Specifications

4.Introduction to instrument functions and buttons

4.1 Host shell jack location and function introduction

The handheld device has two sockets, one is a three-core socket for powering the internal rechargeable battery. The other is a five-core socket for connecting the underwater Doppler current meter.

RS232 socket: The DB9 standard serial port socket at the bottom of the handheld device is used for communication with the computer.

Host display screen: The rectangular box in the upper half of the handheld device is the display screen, where data and operation interfaces are displayed.

Host operation panel: The lower half of the host is the operation panel for users to operate and control the instrument.

4.2 Key introduction

This instrument has a total of six types of function keys, as shown below:

1. Power on/off key I/O: When the power on operation, I/O is the power on/off key, press and hold for 3 seconds, release, and it will turn on.

When shutting down, you must return to the initial main interface, press and hold for 3 seconds, release, the LCD screen goes out, and confirm the shutdown.

2.▲ and ▼: can be used for working sampling time, working interval time, parameter input, up and down movement, etc.;

3. Return key ESC: can return to the previous interface of the system.

4. Confirmation key ENTER: confirm or save the input parameters.

5. Number keys: there are ten number input keys 0, 1, 2, 4, 5, 6, 7, 8, 9, which are used for various digital settings.

6. Delete key DEL key: delete certain data.

5.Instrument connection

1. Use AC power (first use): please take out the accessory battery charger

Insert the DC plug into the charging jack (three-pin jack) on the handheld device, and the AC plug at the other end into the AC 220V socket. During the charging process, it is recommended that the handheld device is turned off. Observe the LED indicator on the charger to see if it is fully charged. After it is fully charged, the charger indicator turns green.

Note: It is recommended to use it after it is fully charged for the first time.

2. Before using the instrument, the flow sensor must be connected to the water handheld host to form a complete system. After the flow meter is placed in the measuring water, the five-core plug at one end of the cable is inserted into the five-core socket of the handheld unit. The instrument can only work properly after it is inserted and tightened.

6.Operation Instructions

6.1 Power on and power off

During the power on operation, the I/O key is the power on/off key. Press and hold the I/O key for 5 seconds and release it to power on. During the power off operation, you must return to the initial main interface, press and hold the I/O key for 5 seconds, release it, the LCD screen goes off, and the power off is confirmed.

After powering on, the company logo and product model are displayed. Press the ENTER key again to display the following main interface

In the main interface menu, divided into three types of functions: setting, collection, query.

6.2 Parameter setting operation

In the main menu, select 1 to enter parameter setting to enter the parameter setting interface. As follows:

1. Time setting

You can set the time by entering the year, month, day, hour, minute, and second. The device comes with a dedicated button battery for the real-time clock. When the device is turned off, the year, month, day, hour, minute, and second continue to run. Generally, there is no need to reset it.

2. Set zero point

The customer can set the starting point of zero flow rate, such as the actual measured data of the measuring instrument is 0.02cm/s. If the user wants to use this flow rate as zero flow rate, he can enter 0.02cm/s in this interface. The flow rate can be calculated from 0.02cm/s. Generally, it can be set to 0.

3. Liquid level compensation

In actual use, the installation position of the Doppler flow meter is not necessarily at the bottom of the canal, but at a position that can represent the overall flow rate of the canal. For example, if it is installed 30 cm from the bottom of the canal, the water depth measured on the Doppler flow meter is actually the distance from the water surface to the installation position. Therefore, it is necessary to enter the liquid level compensation value. If the installation point is 30 cm away from the bottom of the canal, 0.3 meters must be entered at the liquid level compensation. When the handheld device calculates the true depth of the canal, it adds the water depth value measured by the Doppler flow meter to the liquid level compensation value to obtain the true depth of the canal.

4.Channel Selection

They are rectangular section, trapezoidal section and circular section respectively. You can enter the corresponding interface to set the corresponding parameters.

5. Address setting

When measuring flow rates at different locations, users can set corresponding numbers for different locations. When storing data, the numbers are stored together with the data for subsequent identification and observation.

6. Sampling interval

The working interval between each two measurements of the flow meter can be set. (This setting is to reduce the power consumption of the device)

6.3 Measurement and data display operation

In the main menu, select 3 to enter the parameter setting interface. As shown below

In this interface, the current flow rate and flow rate can be changed. To store, press the Enter key to store the current time, station, flow rate, liquid level, instantaneous flow, and cumulative flow in the memory.

6.4 Record query operation

Under the main menu, select 3 to enter the parameter setting interface. As follows:

1. Select 1 query interface, enter the query data, you can view the historical stored data, including site number, storage time, flow rate, liquid level, second flow, cumulative flow, press ESC to exit.

2. Select 2 query interface data clear to enter the clear data interface, press Enter to clear all historical data and cannot be restored, press ESC to exit.

When deleting data, due to the large amount of 32M bytes of data, it takes several minutes. Do not shut down at this time. The interface will prompt as follows:

When the data is deleted, the interface is deleted

3. Enter the data transmission PC. When the handheld device is connected to the computer through the DB9 serial port (baud rate 115200, data bit 8, stop is 1), all historical data can be sent to the serial port assistant for user viewing.

6.5 Operation Example

Assumption: If the channel profile is trapezoidal, the Doppler current meter is placed 0.15 meters away from the riverbed. The measurement site number is 01, and the sampling interval is 15 seconds)

1. When operating for the first time, first enter the parameter setting interface.

You can set the current time.

The default setting of the zero point parameter is 0. If there is no special requirement, no change is required. The liquid level compensation is set to 0.15 meters.

Then enter the channel selection, select trapezoidal, and press the Enter key to enter the parameter setting interface, set the corresponding bottom length and angle, and press ESC to exit after the setting is completed.

Enter the address setting interface, set the address number to 01, and press the ESC key to exit after the setting is completed. Enter the sampling interval interface and set the sampling interval to 15S. After the setting is completed, press the ESC key to exit.

After the parameter setting is completed, press ESC to return to the main interface, enter the data collection interface to view the real-time flow rate, liquid level, second flow rate and cumulative flow rate.

In this interface, if you need to store the current data, please press the Enter key manually, and store it once each time you press it. Press the DEL key to clear the current interface parameters and restart the measurement.

7.Installation requirements

1. The gas cable contains a gas tube, so it cannot be bent excessively to prevent it from breaking; do not use the gas cable as the rope of the flow meter, and use the gas cable to drag the Doppler flow meter;

2. The circular ultrasonic transducer in front of the probe cannot be impacted or scratched;

3. The instrument probe should be avoided from being exposed to the sun for a long time to prevent the temperature from being too high and causing malfunctions;

4. When using an acoustic Doppler flow meter in places with high sediment concentration, the silt on the ultrasonic transducer and pressure sensor should be cleaned regularly to prevent the silt from clogging the pressure sensor.

8.Daily maintenance and repair of the instrument

1. After each use, the underwater sensor should be immediately cleaned with fresh water and wiped dry with a cloth, put back into the original suitcase, and all parts put back in place.

2. The cable of the instrument should be prevented from being scratched or punctured by sharp instruments.

3. The instrument and equipment should be placed in a ventilated and dry place, and should be kept away from corrosive substances. Heavy objects should not be piled on the instrument and equipment.

4. The battery should be charged when used for the first time or when not used for a long time (it must be charged with the charger provided with this instrument).

5. When used in rainy days, be sure to prevent the portable host from being exposed to direct rain.

9.Instrument Packing List

The whole set of portable flow meter includes:

A suitcase, which contains:

1. Doppler flow meter 1;

2. Handheld device 1;

3. Battery charger 1;

4. Serial data cable 1;

5. Measuring rod 1 set;

6. User manual 1 copy;

7. Product warranty card 1 copy

1mm/s Resolution Doppler Flow Meter

0.02m/s～5.00m/s Doppler Flow Meter

7.2V～15V Doppler Flow Meter

KDF1200 Portable Doppler Flow Meter 1mm/s Resolution 7.2V～15V Flow Range 0.02m/s～5.00m/s Images