Flow Range: D4: 0.015 to 4.00 GPH (1 to 250 cc/min. or
0.02 cc/cycle)
D20: 0.075 to 20.00
GPH (5 to 1250 cc/min. or 0.10 cc/cycle)
Accuracy: +/-1%
Repeatability: +/- 0.1%
Maximum Operating
Pressure: Standard: 3,000 psig (207 bar)
High Pressure:
21,000 psig (1448 bar)
Maximum Differential
Pressure: 0250: 5 psi
1250: 15 psi
Temperature
Range: -40˚ to 180˚ F (-40˚ to 80˚ C)
Maximum Viscosity:
100 SSU (25 cp)
NUTATING OPERATING
PRINCIPLE
Measurement occurs
as the result of the dual orbiting motion of the nutating mechanism as it rolls
on the beam.Refer to figures A, B, C and D in sequence. This motion is induced
by the fluid as it passes through the meter.This motion is consistent because
the differential pressure forces are always great enough to ensure that the
nutating mechanism travels the complete volume in each chamber.The process
repeats itself 12 to 250 cycles per second, in proportion to the fluid flow
through the meter. A flow signal is produced by interrupting the light from a
photo-emitting/detecting device. The interruptions are created by a
magnet wire which
tracks the magnet encapsulated in the orbiting nutating mechanism. The
interruptions are then converted to an electronic square wave output, which is
used to quantify the flow.
FLOWMETER FEATURES
The relative
simplicity of the MICRO FLOWMETER makes it far less costly than other positive
displacement flowmeters which may be capable of measuring similar low flow
rates.
Compared to other
positive displacement flowmeters, the MICRO FLOWMETER is less susceptible to
wear. The reasons for this are as follow:
The parts are so
small that the relative velocities amongst the moving parts
are quite low.
All forces acting on
one side of the nutator are largely offset by opposing
forces acting on the
opposite side.
The ends of the beam
are rounded resulting in a rolling motion rather than
sliding during
operation.
Since the moving
parts are not rigidly attached to each other or the motion
detection mechanism,
the MICRO FLOWMETER is capable of service in fluids less
filtered than other
devices which may be capable of measuring similar low flow
rates.
Should the MICRO
FLOWMETER become clogged with debris, it can be easily
disassembled,
cleaned and reassembled with reasonable care in the field.
TD SERIES
SPECIFICATIONS
All materials in
contact with the fluid media are 316 stainless steel and PTFE.
Ranges:
D4: <0.015-4.00
GPH [1-250 ccpm]
D20: <0.075
-20.00 GPH [5 - 1250
ccpm]
Displacement:
D4: Approximately 50
pulses per
cc
D20: Approximately
10 pulses per
Cc
Accuracy:
+/- 1% of scale
Temp. Range:
-40 To +180° F [-40
To +80°]
Repeatability:
+/- 0.1%
Output Signal:
0 - 5 Volt Square
Wave
Maximum Operating
Pressure:
3,000 psig [21 MPa]
Standard
21,000psi [147 MPa]
Added Cost
Option "P"
Process Connections:
1/4"NPT
Max. P: 5 psi [34kPa] D4
15 psi [102kPa] D20
Conduit Connection:
1/2" NPT
Dimensions:
2.50" D. X
4.63 " L. [6.4
cm D. X 11.8 cm L.]
Weight:
[1.32 Kg.]
Viscosity: 100 SSU
[25 cp] Maximum Recommended. Higher Viscosities Reduce
Low Flow Rate
Capabilities.
MECHANICAL
INSTALLATION AND OPERATING CONSIDERATIONS
1. Once installed
and ready to operate, open the bypass and bleed valves wide before slowly
starting fluid flow to the Micro flowmeter. Allow the bleed valve to remain
open until air and vapors which may have been trapped in the Micro flowmeter have
been "bled". If air and vapors are persistent, turn the Micro
flowmeter upside down [compression fittings would be useful] while it is
running for a short time and then return to upright position.
Close the the bleed
and bypass valves and begin normal system operation.[The depicted recommended
installation is for systems operating with pressures greater than 20 psi. The
bypass and bleed arrangement can safely
be omitted from
systems operating at lower pressures].
2. If the Micro flow
meter is subject to hydraulic pulsations, check valves may be
required.
3. If it is
necessary to disassemble the mechanical portion for cleaning or other
reason, ascertain
that the nutator is installed with the inscribed arrow pointing
up [toward the
electronic assembly]. Failure to do so may result in loss of
alignment of the
motion detection mechanism. Use 4 - 5 foot pounds of torque
on the cap screws
when reassembling.
