| 4 Shutdown operation: After each use of the instrument, simply unplug the plug and the instrument will automatically shut down, saving the selected flowmeter model and parameters before shutdown. For the next use, simply plug in the plug, connect the flowmeter, and press the screen change button once to start measuring the current.
4 Computer online operation(This function is not available when there is no requirement for ordering)
Firstly, connect the measuring instrument to the communication port of the computer using a dedicated communication cable. Open the computer and enter the WINDOWS platform - Programs - Accessories - Communication - Hyperterminal. Set the baud rate to 2400, the communication bit to 8 bits, the stop bit to 1 bit, the parity check to none, and the flow control to software mode. Select the correct communication port, connect the signal power line of the measuring instrument, and start the current measurement. After each flow measurement is completed, the measuring instrument automatically sends a set of data to the computer screen for display.
K=7800 C=0.050 T=0106.5 N=0015 V=0.160
K=7800 C=0.050 T=0108.4 N=0016 V=0.165
5、 Maintenance of instruments:
LGY-II portable flow velocity measuring instrument
The maintenance of the measuring instrument must be done by unplugging (disconnecting the power supply) and storing it when not in use for a short period of time. When not in use for a long time, it needs to be charged once every three months.
After each use, rinse the flowmeter and measuring rod with clean water, dry them with a towel, and store them.
6、 The complete set of equipment for the instrument:
One LGY-II speed measuring instrument
LGY-II instrument propeller
Signal link payment
*Communication cable (optional) one set
One charger
enclosure:
One user manual
Special Reminder:
The first charge of the instrument should be greater than3hour.Please set the testing time20More than a second
Please recharge the battery after it has been fully charged each time.(This device has been protected against overcharging)
LGY-IIPortable flow velocity measuring instrument
The LGY-II portable flow meter (referred to as the portable flow meter) is specifically developed for measuring open channel flow velocity and flow in the field by hydrological stations, factories and mines, environmental monitoring stations, agricultural drainage and irrigation, hydrogeological surveys and other departments.
The LGY-II intelligent flow rate meter can be matched with a new type of flow rate rotary plasma sensor, which was successfully developed at the end of 2004 using advanced technology. The rotary plasma helix angle, pitch, manufacturing process, and materials have been redesigned, and the rotary plasma diameters are Φ 15mm and Φ 12mm respectively (the rotary plasma reflective surface adopts advanced electroplating technology, wear-resistant, strong signal). The starting flow rate is ≤ 1cm/s, and the indicators such as starting flow rate, speed measurement range, linearity, concentricity, calibration coefficient, and mean square deviation have been greatly improved and enhanced compared to previous sensors. Flow velocity measurement range: 1-400cm/s. Sampling time: 1 to 99 seconds optional;
Figure 1. Installation diagram of portable flowmeter
The instrument has a simple structure, is lightweight and convenient, consumes less power, has complete functions, high degree of automation, and is stable and reliable. It meets the national standard for open channel flow measurement and is equipped with an 80 degree high-temperature propeller. It is currently a new type of portable flow velocity measurement instrument in China.
1、 Technical requirements for instruments：
KN
Speed measurement formula: V=--------+C (m/s) (automatically calculated)
T
Instrument number:..............., K, C
Speed measurement range: 0.01-4.00 m/s (up to 5.00m/s)
Flow measurement error: ≤ 1.5%
Display screen: 4 x 16 bitsliquid crystal display
Measurement method: Pole positioning measurement
Temperature range: -20 ℃ -50 ℃
Power supply: DC8.4V lithium-ion rechargeable battery, which can work continuously for more than 40 hours after being fully charged
2、 Measurement principle:
This instrument is designed based on the principle of velocity area method for open channel flow measurement. By measuring the velocity, the flow rate Q=V · S (S is the cross-sectional area) can be obtained
1. Flow rate measurement:
When measuring flow velocity, the propeller rotor flowmeter is driven by hydraulic power to rotate, and the built-in signal device generates a rotational speed signal. The flow velocity is calculated using the following formula:
KN
V＝———————— ＋ C（m/s）
T
In the formula: V: Average flow velocity during the flow measurement period (m/s)
K: Hydraulic pitch C of blade: constant of flowmeter
T: Duration of flow measurement (unit: S) N: Number of signals during the T period
When using this instrument, K and C are constants. When measuring flow, as long as T and N are measured, the flow velocity can be calculated.
2. Calculation of traffic:
Flow measurement is based on the velocity area method of open channel flow measurement, which first measures the velocity and then multiplies it by the cross-sectional area to obtain the flow rate.
3、 Operation and use of instruments:
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ZMLSY-1.0 7.2V
K=.0288 1V=0.000
T=100 0N0000.0
Q=000000.000m3\\h
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Under normal circumstances,Plug in the plug to power on, unplug to power offThe instrument can be powered on to display the parameters of the flow meter selected during the last shutdown. The parameter settings are shown in the figure: If the parameters are the same as the certificate, you can enter the flow measurement.
Figure 1. Measurement display
There are three buttons on the instrument:
menu open.stop move up
right shift
3.1 Parameter setting operation:
3.1.1Parameter setting one:Check if the display screen matches the parameters of the current meter used. If not, press the MENU key to enter Settings 1 and modify the display screen using the right and up keys. For example, if the C value is 0.0150, first press the right shift key to move the cursor to C=. 010Press the up button at position 0, add 1 each time, and repeat until the value of the number of digits where the cursor is located matches the required value *, which is C=0.0150.
The method for modifying K value and measuring time T is the same as above. First, press the right shift key to shift, then press the up shift key to add until it is correct. Press the wrong button to repeat the above operation.
In the display screen, please input the K and C coefficients according to the parameters of the appraisal certificate:
TThe measurement time unit for automatic measurement is seconds
3.1.2Press the menu key to enter Settings 2
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set up2
automatic- 0
delayed- 3
cross section- 01.005 m2
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set up1
pitch- K=.9710
constant- C=.0170
duration- T=100.00
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On the display screen, the automatic "0" symbol indicates automatic measurement, and setting it to "0" indicates automatic measurement. If manual measurement is required, the symbol should be set to "1".
On the display screen, a delay of 3 seconds indicates that the measurement interface is entered after the settings are completed. After 3 seconds, automatic measurement processing will begin. If it is automatic measurement, the instrument will automatically repeat the measurement times (with a delay time interval).If measuring manually, press the start stop button to measure and stop when needed. After reading the data, press the start stop button once to proceed to the next measurement.
Output of cross-sectional area: After setting the unit in square meters, the flow rate of the cross-sectional area can be obtained using the formula Q=V · S (where S is the cross-sectional area)
3.1.3Version number communication display communication method (default no communication)
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set up4
Baud rate— 9600
stop bit— 1
check bit—N
communication—RS232
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set up3
version—ZMLSY -1.0
model—1206B
communication—RS232
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3.2 Measurements
After setting the parameters correctly, press' right-click keyboard+move up 'at the same time to save the parameters and return to the measurement state;
Entering the measurement state, as shown in the figure: If it is automatic measurement, the instrument will automatically calculate the flow velocity value according to the formula after each measurement and display 1V=0.000M/S. After a fixed display of 3-5 seconds, the measurement will be automatically repeated, but the flow velocity value will remain displayed until the end of the next measurement. If measured manually, after each measurement is completed and the reading is finished, press the start stop button once to proceed to the next measurement. When measuring, when the * signal arrives, it can be seen from the display that time T starts counting and N starts counting. When time T reaches the set time and another signal is received, the instrument automatically turns off T and N, and calculates the flow rate V. After a delay of 3-5 seconds on the display, the instrument automatically starts the next flow measurement and repeats the above process. In this measurement, the displayed V value is the previous flow rate value for reference and recording.
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