current meter ( d3 teknik sipil its )
DESCRIPTION
praktek hidrologi dan hidro.lika terapan D3 teknik sipil itsTRANSCRIPT
As we know,the current meter is used to measure the velocity at a point in the flow cross-section.It consist s essentially of a rotating element which rotates due to the reaction of the stream current with angular velocity proportional to the stream velocity.
The typical relationship:
v = aNs + b
v = stream velocity at the instrument lovation in m/s
Ns = revolutions per second of the meter
a,b = constants of the meter
FOR MANUAL CURRENTMETER
For standard size 12.5 cm diameter Price meter(cup type):
a=0.65 , b= 0.03
For smaller meters of 5 cm diameter cup:
a= 0.30 , b= 0.003
For value of revolutions per second of the meter:
Ns = 0.002 m/sec
THE COMPONENT OF CURRENTMETER
Current meter-reading the velocity
Censor-detect the water velocity
Propeller-prevent the stream flow of water.
Electrical connection-Supply power
OPERATIONAL MECHANISM Assemble all of the current meter segment such as
propeller,censor,holder connecter and electrical connection.
Make sure that the error from the holder is parallel to the censor device.
Switch on the current meter.
Before taking the reading of current meter, rezero the meter.
Make sure that the censor was in a calm water before rezero the meter.
Two ways to rezero:
-set 0.0000
-Adjust zero
Read the value of velocity from the current meter.
REFERENCES: http://www.jfe-alec.co.jp/html/aem1-de.htm
http://www.google.com.my/url?sa=t&rct=j&q=aem1-d&source=web&cd=8&ved=0CFUQFjAH&url=http%3A%2F%2Fwww.candv.co.kr%2Fdata%2FAEM1-D.pdf&ei=FqrdTrLmC4fyrQfTidnUCA&usg=AFQjCNExgWLOvB27KsMl9MtFS6UnmR-AOA
Hydrology Reference Modul