B U L L E T I N
824A
I N S T A L L A T I O N & O P E R A T I O N
SFD-2 Microwave
Solids Flow Detector
separate components are connect-
ed via a low-voltage 3-wire system.
The SFD-2 consists of a split archi-
tecture design incorporating a sensor
head and a separate power
supply/conditioner. The SFD-2 sen-
sor head is a microwave transceiver
(combination transmitter/receiver)
encased in a watertight aluminum
housing with a screw-on cover. A
process seal (Teflon
®
or Ryton
®
-equiv.)
acts as a transparent window through
which the microwave signal is trans-
mitted and the reflected return signal
is received. The transceiver module
generates and transmits a microwave
signal into the area where the flow is
being monitored. The reflected signal
is analyzed whereby a frequency
shift in the reflected signal caused by
material movement is decoded as a
flow condition. The resultant output is
carried back to the power
supply/conditioner PCB where the
signal is indicated by an output relay and LEDs. This PCB also provides
the power to drive the sensor head and is the location for control settings
such as sensitivity, hold-off delay, hold-on delay and fail-safe selection.
Thank you for purchasing a
quality product manufactured by
Monitor Technologies LLC. We
realize that you do have a choice
of vendors when procuring flow
sensors and we sincerely
appreciate your business.
This manual contains the
information necessary to ensure
a safe and successful installa-
tion. Please read and comply with
the section on pages 7 & 8 of this
manual pertaining to SAFETY.
Doing so will ensure proper
operation of the equipment and
the safety of all personnel.
In the event that information con-
tained herein does not complete-
ly satisfy your requirements or
answer your questions, you may
contact Technical Support on our
website www.monitortech.com,
by telephone at 800-766-6486
(630-365-9403), or by fax at
630-365-5646. If your SFD-2 ever requires service either in or out
of warranty, please contact us and obtain an RMA number prior to
shipping the unit to us.
Monitor's SFD-2 Microwave Solids Flow Detector is a high qual-
ity, industrial grade instrument capable of providing a signal indi-
cating flow/no-flow conditions of solids and powders in pneumat-
ic pipelines, gravity chutes and feeders. This non-contact detec-
tor contains no moving parts or probes that can wear out or
break off in the material flow, thus ensuring process integrity.
The SFD-2 uses low power microwaves to sense motion within
the vessel or channel being monitored. Microwave technology is
used in the SFD-2 because the microwaves are virtually unaf-
fected by heat, humidity, ambient light, pressure, vacuum, high
or low temperatures, or dust, thus providing maximum effective-
ness in industrial applications.
Every SFD-2 assembly consists of a sensor head and a remote
power supply/conditioner board. The remote board can be pur-
chased with or without a NEMA 4X fiberglass enclosure. The two
M o d e l S F D - 2
t
No maintenance
t
Non-contact operation
t
Non-intrusive flush mounting
t
Immune to environmental conditions
t
Dust-ignition proof design
PRINCIPLE OF OPERATION
CHOOSING THE SYSTEM LOCATION
(See Figure 1)
1) Hazardous/Non-hazardous
- The sensor portion of the split
architecture is designed for use in Hazardous Locations associ-
ated with combustible dusts. The location chosen must comply
with the classification listed in the specifications. The power sup-
ply/conditioner is to be used in non-hazardous environments
unless the user chooses to house the PCB in a customer sup-
plied enclosure which has the appropriate hazardous location
classifications.
2) Temperature Limits
- The operational temperature limits for
the sensor and power supply/conditioner must be satisfied.
3) Accessibility
- Since the sensor head usually does not need
adjustment after installation, it can be located at a remote loca-
tion not as accessible to personnel. The power supply/condi-
tioner should be located where personnel can easily access the
PRE-INSTALLATION CONSIDERATIONS
GDR
JSC
APR 18 2014
DOC-001-824A 8
