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NEYRFLUX ® CURRENT METER
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  The
meter for hydrologists
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- fully sealed electric contacts
- simple construction, no maintenance
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| Application
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Measurement of current velocity, e.g. watercourses,
canals, etc.
Discharge can be calculated from velocity measurements if
the cross-sectional area of the watercourse or channel is
known.
The Neyrflux current meter can be fitted to various types
of mountings and connected to various types of signal
receivers. |
| Principe
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The propeller is rotated by the current flow and
drives an electric contact mechanism. The frequency of
contact make and break is proportional to the rotational
speed of the propeller; the accurate relationship between
rotational speed and current velocity is obteined by
calibration. |
| Advantages
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- Very simple apparatus, with limited
number of parts.
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- Corrosion resistant components:
fibreglass reinforced plastic ans
stainless steel.
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- Very simple to use: no oil filling and
virtually no maintenance (simply wash in
water from time to time).
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- Propeller and rotating parts of very low
weight and inertia, making for great
sensitivity and good accuracy of
measurement as well as long bearing life.
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- Bearings with a very low friction
coefficient, advantageously replacing
ball bearings which are more sensitive to
foreign matter in suspension.
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- Shape and dimensions of body and mounting
favourable to accuracy of measurements.
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- Propeller with swept leading edges
reduces the risk of trapping floating
bodies.
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- Releable rotation detection system,
protected from contact with the fluid.
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- Full interchangeability of all parts.
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- Direct mounting on rod D 20 mm and
NEYRTEC sinkers.
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| Characteristics
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Measuring range: current velocities from 4
cm/sec. to 6 m/sec.
Current meter with propeller: length: 262 mm.
weight: 480 g.
Propeller: diameter: 10 cm - nominal pitch: 0.25 m
- actual pitch: see mean calibration formula sypplied
with instrument.
Electric contacts: one single-throw contact per
propeller revolution.
Breaking capacity of magnetic switch: 10 volts, 2
mA, on resistive load. |
| Accuracy
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Mean calibration formula: probable error less than
±1%.
Individual calibration is not required for new equipment.
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| Description |
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a) Propeller assembly This consits of a
plastic propeller (10) the propeller hub (13) screws-on
to a bush (8) fitted with two low-friction bearings (12).
The propeller-bush assembly rotates on a stationary
spindle (9). Bush (8) is retained on spindle (9) by a nut
(11) fitted before the propeller is screwed on.
The axial thrust due to the action of the fluid on the
propeller is taken up by a bearing plate (3) fixed inside
the propeller ans a ball bearing (2) set in the end of
spindle (9).
b) Contact unit
The contacts, in a shut-tight capsule (15), moved by
magnet (14), and their connections, are moulded in a
plastic material.
This unit - the magnetic contact (5) - fits into the
chamber et the rear of the shaft (9).
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| Specifications |
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Ref. 2143 A: Neyrflux current meter, with 0.25
m pitch propeller, terminals, stream-lined screw (6).
Possible direct mounting on D 20 mm pole, NEYRTEC slide
and sinkers. |
| Spares |
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Ref. 2147 A: Propeller - pitch: 0.25 metres,
dia. 100 mm.
Ref. 2141 G: Bush with 2 bearings and magnet.
Ref. 2141 K: Spindle (9) and nut (11).
Ref. 2143 L: Magnetic contact with seals (15).
Ref. 2143 M: Current meter body (1).
Ref. 2143 N: Stream-lined screw, inox, to clamp
the current meter on D 20 mm pole (6). |
| Accessories |
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Ref. 2171 A: Electric cable for connection
between the current meter 2143 A and the NEYRTEC
receivers (counters) suitable to midget current meter
Beauvert ans SIAP current meter.
Ref. 2143 C: Case for current meter NEYRFLUX and
accessories.
Electric signal counters
See pamphlet M 22.
Mounting (Rigid Type)
See pamphlets 23.51 and 23.71.
Sinkers, winches and cranes
See pamphlets M 241, 242 and 243.
Cableways
See pamphlet M 244. |
