Seametrics EX80 Series v.1 - Manual (Page 3)

GENERAL INFORMATION
The EX80-Series are electromagnetic inser tion flow
sensors for use in conductive liquids in pipe sizes 1” to
8” (25mm to 200 mm.) Lacking moving parts, they are
well suited for applications which have particulates in the
fluid and are therefore problematic for impellers or turbines.
Other advantages are insensitivity to viscosity and
tolerance for pulsating flows. This makes them a good
choice with fluids with var ying viscosity and 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 FS10 is a flow switch module, and the
DL75 is a datalogger.
Any of these modules except the DL75 (which is wall-mount
only) 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.
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 necessar y 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 inser tion flow sensors, the
EX80-Series extend into the pipe and measure the velocity
of the fluid in a par ticular area of the pipe. The chosen
inser tion 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 8”. Each fitting
insures that the flow sensor is installed at the correct point.
Ever y flow sensor and ever y 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) is established through testing with various standard
schedules of pipe and 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
AR
CH
IVE
D
(Includes Dates 6/14/04 to 5/05)