F-4
FLOW SENSORS – ELECTRONIC
Visit www.GemsSensors.com for most current information. RFO Type / p1of2 / 30-JUL-14
Body
Material
Port Size
NPT
Flow Range – GPM Part
Number
Low Range*
(Accuracy)
Standard Range
(Accuracy)
Polypropylene .25˝ 0.1 to 1.0 (±7.0%) 0.5 to 5.0 (±7.0%) 155421
.50˝ 1.5 to 12.0 (±7.0%) 4.0 to 20.0 (±15.0%) 155481
Brass
.25˝ 0.1 to 1.0 (±7.0%) 0.5 to 5.0 (±7.0%) 156261
.50˝ 1.5 to 12.0 (±7.0%) 4.0 to 20.0 (±15.0%) 156262
.75˝ — 5.0 to 30.0 (±15.0%) 194761
1.00˝ — 8.0 to 60.0 (±15.0%) 194762
Stainless
Steel
9/16˝-18** 0.1 to 1.0 (±7.0%) 0.5 to 5.0 (±7.0%) 165071
.50˝ 1.5 to 12.0 (±7.0%) 4.0 to 20.0 (±15.0%) 165075
.75˝ — 5.0 to 30.0 (±15.0%) 194763
1.00˝ — 8.0 to 60.0 (±15.0%) 194764
3.06˝ (77.7 mm)
2.50˝ (63.5 mm)
.64˝ (16.3 mm)
3.06" (77.7 mm)
2.50" (63.5 mm) .25" (6.3 mm)
.80˝ (20.3 mm)
2.38˝ (60.5 mm)
1/4" NPT-2.01" (51.1 mm)
1/2" NPT-2.21" (56.1 mm)
3/4" NPT-2.51" (63.8 mm)
1/4" NPT-.64" (16.3 mm)
1/2" NPT-.70" (17.8 mm)
3/4" NPT-.70" (17.8 mm)
Don't Use - Replaced with RFO B&SS 1/4" &1/2" art
3.01˝ (76.4 mm)
2.50˝ (63.5 mm)
2.32˝ (58.9 mm)
1/4˝ PORTS =
80˝ (20.3 mm)
1/2˝ PORTS =
87˝ (22.1 mm)
2.50˝
(63.5 mm)
3.94˝
(100 mm)
2.95˝
(74.9 mm)
1.06˝
(26.9 mm)
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RoHS
Flow Rate Monitoring – RFO Type
4.5 to 24 VDC Pulsed Output
GEMS Sensors popularized the RotorFlow’s paddlewheel design by combining high
visibility rotors with solid-state electronics that are packaged into compact, panel
mounting housings. They provide accurate flow rate output with integral visual
confirmation...all with an unprecedented price/performance ratio. RFO Types feature a
VDC pulsed output.
Typical Applications
• Water Purification/Dispensing Systems • Chemical Metering Equipment
• Lasers and Welders • Water Injection Systems
• Semiconductor Processing Equipment • Chillers and Heat Exchangers
Specifications
Wetted Materials
Body Brass, 316 Stainless Steel or Polypropylene
(Hydrolytically Stable, Glass Reinforced)
Rotor Pin Ceramic
Rotor PPS Composite, Black
Lens Polysulfone1
O-Ring Viton® (Alloy Bodies); Buna N (Polypropylene Body)
Low Flow Adaptor Glass Reinforced Polypropylene
Operating Pressure, Maximum Optional SS Face Plate 500 PSI
Brass or Stainless Steel Body 200 PSIG (13.8 bar) @ 70°F (21°C),
100 PSI (6.9 bar) Max. @ 212°F (100°C)1
Polypropylene Body 100 PSIG (6.9 bar) @ 70°F (21°C),
40 PSI (2.8 bar) Max. @ 180°F (82°C)
Operating Temperature,
Brass or Stainless Steel Body -20°F to 212°F (-29°C to 100°C)
Polypropylene Body -20°F to 180°F (-29°C to 82°C)
Electronics 150°F (65°C) Ambient
Viscosity, Maximum 200 SSU
Input Power 4.5 VDC to 24 VDC
Output Signal 4.5 VDC to 24 VDC Pulse. (Sourcing)
Pulse Rate Dependent on Flow Rate, Port Size and Range.
Current Consumption 8 mA, No Load
Current Source Output, Max. 70 mA
Frequency Output Range 15 Hz (Low Flow) to 225 Hz (High Flow)
Accuracy See Table Below
Electrical Termination 22 AWG PVC-Jacketed, 24˝ Cable. Color Coded:
Red = +VDC; Black = Ground; White = Signal Output
Notes:
1. For higher pressure/temperature ratings, stainless face plates are available. Consult factory.
How To Order
For standard configurations, specify Part Number based on desired body material and
port size.
Note: Improved accuracy can be achieved by calibrating the individual
RFO unit.
* With use of Low Flow Adapter supplied.
See Page F-8 for more information.
** Straight thread with O-ring seal.
– Stock Items.
File No. E45168
Dimensions
Polypropylene Bodies
Brass and Stainless Steel Bodies - .25˝ and .50˝ Ports
Brass Bodies – .75˝ and 1.00˝ NPT Ports
High Resolution
Black Rotor
PPS composite. Each of the six
rotor arms is magnetized. A PTFE
loaded bushing ensures long life.
F-5
FLOW SENSORS – ELECTRONIC
Visit www.GemsSensors.com for most current information.
RFO Type / p2of2 / 30-JUL-14
Output Frequency – Hz
RFO Model – Based on Port Size
Flow Rate
(GPM) .25˝ .25˝ with
Adapter* .50˝ .50˝ with
Adapter* .75˝ 1˝
0.10 13
0.25 41
0.50 15 90
0.75 137
1.0 34 186
1.5 54 17
2.0 73 25.9
2.5 90 34
3.0 110 43
3.5 128
4.0 148 34 60
4.5 168
5.0 185 44.8 76.7 24
6.0 55 94
7.0 65.9 111
8.0 76 129 22
9.0 87.5 147
10 99 165 61 30
11 110 185
12 122 204
13 135
14 147
15 158 93 43
16 170
17 183
18 195
19 207
20 220 128 60
25 163 74
30 196 91
35 107
40 123
45 137
50 153
55 170
60 185
SENDS A VOLTAGE PULSE
WITH EACH PASS OF
MAGNETIC FIELD
HALL EFFECT SENSOR
MAGNETIZED ROTOR
FLOW IN
FLOW OUT
PARTIAL
CUTAWAY
TIME
12
0
+VDC
TIME
12
0
+VDC
TIME
12
0
+VDC
TIME
12
0
+VDC
9
6
3
00.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 2 3 4 5 10 15
12
9
6
3
00 1 2 3 4 5 10 15 20 25
1/4˝
Ports
1/4˝ Ports 1/2˝ Ports
1/2˝ Ports
Flow Rate – GPM
Flow Rate – GPM
PSI PSI
12
9
6
3
0010 20 30 40 50 60 70 80 90
110
100
3/4˝
Ports
1.0˝ Ports
Flow Rate – GPM
PSI
Operating Principle
1. As liquid passes through the RotorFlow body, the magnetic rotor spins at a rate
proportional to flow. This causes a series of magnetic fields (the rotor vanes) to excite
the Hall Effect sensor, producing a series of voltage pulses.
2. The output pulses (RFO) are at the same voltage level as the input (4.5 - 24 VDC)
with a frequency proportional to the flow rate. The output signal can be utilized by
digital rate meters totalizers or other electronic controllers. RFA Type analog sensors
condition the output signal to 0-10 VDC.
3. RotorFlow Indicators may be mounted with flow entering either port. Performance
is optimized by positioning ports at the top of the unit, in a horizontal plane.
Frequency vs. Flow Rate-Typical
Signal Output
Output signal for RFO Types is an on/off pulse of the
DC voltage supplied to the unit, it is compatible with all
digital logic families. Input voltage range is 4.5 to 24
VDC. Frequency of the output pulse is proportional to
the flow rate and ranges from approximately 15 Hz at
low flow to 225 Hz at high flow.
Example:
Low Flow
High Flow
Note: Consult factory for flow rate/frequency curves.
Pressure Drop-Typical
Standard
Flow
Range
Units
Low Flow
Range
Units
High Flow
Units
*Low Flow Adapter
RFO TYPE
