gEnEral inFormation
The EX80-Series are electromagnetic insertion flow sensors
for use in conductive liquids in pipe sizes 1” to 10” (25mm
to 250 mm.) Lacking moving parts, they are well suited
for applications with particulates in the fluid that are
problematic for impellers or turbines. Other advantages are
insensitivity to viscosity and tolerance for pulsating flows
such as with air-driven diaphragm pumps.
modularity.
Simplicity and modularity are at the core of
the EX80 design. The basic flow sensor has one output,
which is pulse proportional to flow rate. The FT420 module
can be added to provide indication, 4-20 mA, and flow
rate setpoints. The AO55 adds 4-20 mA analog only (blind
transmitter). The FS30 is a flow switch module, and the
DL75 is a datalogger. Any of these modules can be ordered
pre-installed on the flow sensor or in a wall mount housing,
and any can be retrofitted to the EX80-Series sensor in the
field. The EX80 is also compatible with the FT520 batching
flow processor.
output.
The basic pulse signal is compatible with many
controls, with PLC’s and irrigation or water treatment
controllers being the most common. For these applications
it is sometimes necessary to add a pull-up resistor, if the
controller is not designed for a current-sinking input. See
the section on “Connecting to PLC’s and other Controllers”
before connecting to a non-SeaMetrics control.
insertion Depth.
Like all insertion flow sensors, the EX80-
Series extend into the pipe and measure the velocity of the
fluid in a particular area of the pipe. The chosen insertion
depth is the “critical point”, or the area of the flow stream
which maintains the average velocity across a wide range
of flow rates. This is necessary because the shape of the
velocity profile changes as the rate increases. (It transitions
from a “bullet” to more of a “plug” shape).
Fittings.
Since the EX80-Series sensors are not adjustable,
they must be purchased with fittings appropriate to the
application. The EX81 is sized for fittings of 1” to 3”. The
EX82 is for fittings of 4” to 10”. Each fitting insures that
the flow sensor is installed at the correct point. Every
flow sensor and every tee fitting is wet calibrated. Saddle
fittings are normally not wet calibrated, because they are
field-installed on a pipe. In PVC however it is possible to
order a saddle pre-installed on a standard length of pipe,
in which case the entire assembly is wet-calibrated. For all
other saddles, the K-factor (pulses per gallon), established
through testing with various standard schedules of pipe, is
provided with the saddle.
Page 1
EX80 PartS Diagram
Sensor
O-Ring
Retaining Slot
Lower Housing
Cable-Seal Strain Relief
Housing Screw (connect ground to one)
Cover or Module
tablES anD DiagramS
AR
CH
IVE
D
(Includes Dates 6/28/05 to 10/06)
