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<br />fjIJJ353
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<br />Radio Reporting Stream Gauge
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<br />The Radio Reporting StreUD Gauge, ahown in Figure J, con.i.t. of the
<br />Handar 40'A Standpipe Tower wi th cover, mut, antenna, the '8,A OaU Tuns-
<br />mitter, and the Multi-frequcocy VI-E Synthesized Radio tran.mitter or the
<br />UHF Radio Tran.mitter. The water level sen.or, the Handar 4J6A Shaft
<br />Encoder, is cabled to a neuby stilling well. A pulley, upe, float, and
<br />counterweight, attached to the Shaft Encoder, monitor the level of the
<br />water in the atilling well. Rainfall and other wuther aen.ora can be
<br />added to this atreUD gauge, as required.
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<br />Figure J al.o .how. an arrang~ent where all equipment is hou.ed in a
<br />Gauge HOUle, which provides .helter for rhe 58' Oau Tunl.lDirrer, the 4J6A
<br />Shaft Encoder, and an adequate s uucture for mount ing an ant~nna and mas r.
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<br />HIndu 4'6A Shah IlDcodu. The Shaft Encoder, shown in Figure 4,
<br />consi.ts of onl, one moving parr, a rotating magnetic rotor, thus greatl,
<br />improving reliabilit,. Magnetic polea, apaced 1/IOOth of a revolution
<br />apart provide electronic puhes u the, pu s over two semiconductor Hall
<br />Effect devicCl. Consequent 1" accuracy is 0.01 foot for a one foot circllD-
<br />ference pulley attached to the shaft. Direction of rotation is determined
<br />by a phue shift between the two pulae signals and a phue detector in the
<br />'8' Data Tran.mitter.
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<br />Although the 4J6A hu a vcr, high resolution of 0.01 foot, it is
<br />possible, u.ing .witches in the 58' Data TranROitter, to reduce its "effec-
<br />tive transmillion rClolution." The .haft encoder will tun.mit onl, on
<br />ever, nth cycot depending on the setting of a 0 to P switch. Thi. allow.,
<br />for esample, turbulent water level to be effectivel, averaged '0 that radio
<br />tranamillions are only made, say, ever, 0.03 foor change in water level.
<br />This feature is also quite convenient during heavy rainfalls, particularl,
<br />in large network., because the nlllllber of radio tun.minion. can be ligni-
<br />ficantl, reduced, thus lowering the possibilit, of IF interference.
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<br />This simple, but reliable device has been tested and u.ed by the
<br />National Weather Service Test and Evaluation Laboratories in Virginia. The
<br />lack of guu, cams, IwitchCl, erc. in the de.ign is the ba.is for it.
<br />ucellent reliabilit, in runed field condition..
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