Dwyer LOFM User Manual
Series LOFM
LOW FLOW ELECTROMAGNETIC
FLOW SENSOR INSTRUCTIONS
F-LOFM
GENERAL INFORMATION, FEATURES and SPECIFICATIONS
INSTALLATION and CONNECTIONS
The LOFM Electromagnetic Flow Sensor is designed for low-ow
chemical injection or difcult-to-meter applications with pulsating metering pumps in 3/4” to 1/4” pipe/tube. The housing is
made of sturdy splashproof HDPE plastic.
With no moving parts, the LOFM can handle uids containing particulate matter without clogging or jamming, keeping
maintenance at a minimum. With no metallic parts (100%
PVDF body and PVDF carbon ber-lled electrodes), the meter is corrosion-resistant and compatible with a wide range of
chemicals. Accuracy is maintained with conductive uids (>20
microSiemens) of varying viscosities and densities.
FEATURES
8-pin circular bulkhead connector, 20’ (6 m) cable provided
Internals made of chemical and corrosion-resistant PVDF
Sturdy HDPE housing
FlareTek® ttings
are standard
Mounting bracket
The LOFM meter is compact enough to t most pump/injection
systems. With zero straight pipe required after an elbow, it can
be easily mounted in tight spaces. The mounting bracket adds
stability.
The LOFM meter has optocoupled current sinking or current
sourcing pulse output that can be connected to the Dwyer’s
RTI rate/total display or a 4 to 20 mA loop for powering analog
devices. Outputs and power are provided through a cable with
8-pin female circular connector.
Threaded NPT adapters
can be purchased separately
(available in PVC or PVDF)
INSTALLATION
Positioning. The LOFM can be mounted vertically or horizon-
tally. It is important to choose a position that will ensure full
pipe. (Under certain conditions of empty or partially-full pipe
the meter may give a pulse out when there is no ow.) With a
zero straight pipe requirement after an elbow, the LOFM meter
can be installed in tight spaces.
Mounting. The LOFM may be supported by its piping connections IF the piping is rigid. The meter and pipe must be perfectly aligned with no exion at the ttings to prevent damage
to the meter and leakage. It is highly recommended to use the
mounting bracket provided. The mounting bracket uses two #8
screws on a 1.5” center.
Piping. Metal pipe, metal tube, or plastic tubing can be used
with the meter. The standard FlareTek® ttings can be used
with or without NPT adapters on 3/4” or 3/8” pipe. If used, NPT
adapters should be hand-tightened onto the ttings to avoid
damage to internal O-ring seals. Thoroughly clean the pipe
threads and nose and apply Teon tape to adapter threads.
Hold ttings/adapters with a wrench while tightening the pipe
to prevent damage to the meter. If using FlareTek® ttings, follow the installation instructions provided with your are tool.
Power Supply. A 12 VDC linear, regulated power supply with an
output current of at least 0.25 A is recommended. If a switching power supply must be used, consult Seametrics for approved manufacturer’s model numbers.
CONNECTIONS
Power and signal connections are provided through the 8-pin
male bulkhead connector on the meter housing (20’ (6m)
cable provided). See the Pin Assignment and Connections
diagrams below.
5
4 6
3 7
8
2 1
Cable Plug Contact
Arrangement
In addition, it is necessary for proper operation to ground the
unit to a good quality earth ground. Assure negative power
supply is grounded to earth and to the entire electrical/mechanical system. If metal piping is used, jumper inlet and
outlet pipes together and connect to ground for best results
in metering accuracy.
Pin# Function Color
1 Pulse (-) White
2 Ground Brown
3 Pulse (+) Green
4 4-20 (+) Yellow
5 Not Used Grey
6 Not Used Pink
7 4-20 (-) Blue
8 Power (+) Red
SPECIFICATIONS*
Pipe Size
Fittings
Materials Body
Electrodes
Ground
Housing
Fittings (FlareTek®)
Adapters (NPT)
O-Rings (for NPT)
Temperature Ambient
Fluid
Pressure
Flow Range -1
Accuracy -1
Output Signal
-1
Power
Conductivity
Empty Pipe Detection
Environmental
*Specications subject to change
**Requires adaptors
FlareTek® is a registered trademark of Entegris, Inc.
-2
-2
-2
3/4”, 1/2”, 3/8”, 1/4”**
FlareTek® ttings standard in 3/4” or 3/8” owbody; NPT threaded adapters also available
PVDF
PVDF carbon ber-lled
PVDF carbon ber-lled
HDPE with glass ber
PVDF
PVC or PVDF
EPDM or Fluoroelestomer
0˚ to 130˚ F (-18˚ to 54˚ C)
32˚ to 200˚ F (0˚ to 93˚ C)
150 psi
20 GPM Max. (0.2 GPM cut off)
3 GPM Max. (0.03 GPM cut off)
+/- 1%, +/- 0.005 GPM of reading across rated range
+/- 1%, +/- 0.002 GPM of reading across rated range
Optocoupled current sinking or current sourcing pulse output: 30 Vdc, 5 mA max;
4 to 20 mA current loop: 7 Vdc plus load voltage drop min; 50 Vdc max
PE102-075: 500 pulses/liter (1892 pulses/gallon),
PE102-038: 1,000 pulses/liter (3785 pulses/gallon).
10-15 Vdc, 150 mA (linear power supply recommended)
>20 microSiemens
Hardware/software, conductivity-based
NEMA 4X (IP 66)
Dual Power Supply with Loop Isolation
4-20 mA
loop
12-24
Vdc
FlareTek® is a registered trademark of Entegris, Inc.
4 8
LOFM
7
4-20
device
2
Sensor Input
3
1
Power
RTI
12-15
Vdc
4-20 mA Device and RTI with Single Power Supply
12-15
Vdc
4-20 mA
loop
4 8
LOFM
7
4-20
device
2
3
1
Sensor Input
RTI
Power
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