Portable River Water Flowmeter Velocity Meter
CHL-S3A
CHL-S3A portable current meter is developed for the specific measurement of the flow rate for the hydrometric station, factories and mines, environment-protection monitoring station, irrigation and drainage on the farmland and hydrogeology survey, etc.
CHL-S3A intelligent current meter can be equipped with the new sensor of the flow rate rotating propeller. The sensor is developed by the advanced technology at the end of 2004. The helical angle, thread pitch, craftsmanship and materials are all been redesigned., the initial velocity ≤1cm/s. Indicators like initial velocity, measurement range, linearity, concentricity, the Calibration coefficients and mean variance are been greatly improved. The measurement range of the flow velocity: 1~400cm/s and that of sampling time: 1~99 seconds.
The device is simple and convenient, energy saving, stable and reliable. It possesses complete functions and a high automaticity in accordance with the national measurement standard of open channel. Equipped with a rotating propeller which can endure 80 ℃， it is a new portable current meter in China.
Technical requirement of the device.
KN
Velocity measurement formula：V ＝ ——————— ＋ C(m/s)(automatic calculation)
T
Serial number： 、K 、C
Range of the velocity measurement：0.01-4.00 m/s (5.00m/s is also attainable)
Error in current measurement：≤1.5%
Display screen：4×16 liquid crystal display
Measurement mode： Dip stick location measurement
Temperature range：－20℃- 60℃
Power supply: DC8.4V Li-ion rechargeable battery, continuous operation of above 40 hours after complete charge.
II: measurement principal
The device was developed with the flow velocity-area method in the open channel measurement. After obtaining the flow velocity, the flow quantity can be obtained through the formula Q=V·S(S is the section area)
The measurement of the flow velocity
In the measurement, the rotor current meter was rotated by the water power, the signal device generates the revolution signal, and the flow velocity can be calculated by the following formula:
KN
V＝———————— ＋ C（m/s）
T
In it ：V：The mean flow velocity during the measurement（m/s）
K：Screw pitch C：Constant of the current meter
T：the amount of time of the measurement（unit: s）
N：The number of signals during T
During the use of the device, K and C both are constants. The flow velocity can be calculated once the value of T and N are obtained.
The calculation of volume of flow
By the flow velocity-area method, the volume of flow can be obtained by multiplying the flow velocity and section area which were obtained in the measurement.
Three: operation of the device
Normally, plug in to start up and unplug to shut down. The moment the device is plugged in, the screen will display the current meter parameter used last time. The parameter setting is illustrated as follows: Measurement can be conducted once the parameter coincides with the certificate.
