Toshiba Electromagnetic Flowmeter LF470/LF612 - Manual (Page 6)

TIC-LF470B
6
Wiring Precautions
(1) Connect the following two cables correctly:
1) signal cable (on the right facing the LF470)
2) excitation cable (on the left facing the LF470)
(2) Do not bend apply excessive force to these cables.
Piping Precautions
(1) Connect the fluid pipe to the pipe connection port
using a joint that matches the Rc (PT) female screw.
Use seal tapes when connecting the pipe to the port
to prevent a fluid leakage. Do not tighten the
connection screw too much.
(2) Design piping so that the detector’s pipe is always
filled with the fluid to be measured, whether the
fluid is flowing or not.
(3) The fluid to be measured must be held still in the
pipe when the LF470 is being adjusted. If the fluid
can not be stopped after the LF470 installation,
install a bypass pipe in parallel with the LF470
flowmeter.
Meter size
To select the meter size:
See Table 3 to 4 and find meter sizes within the
velocity of 0.3 to 32.8 ft/s (0.1 to 10m/s) for a
specified full-scale (measuring range high limit)
flow. Select one that has its full-scale velocity
between 3.0 and 10 ft/s (1 and 3m/s).
Note: Make sure the full-scale flow rate used for the final
planning stage stays within 32.8 ft/s (10m/s) in
terms of flow velocity.
Table 2. Meter size and Flow Velocity (SI unit)
Unit:gal/min
Meter size
(inch)
0.98 ft/s 3 ft/s 10 ft/s 32.8 ft/s
1/10” 0.02334 0.07115 0.2372 0.7781
1/6” 0.05975 0.1821 0.6071 1.992
1/4” 0.1344 0.4098 1.3660 4.482
Table 3. Meter size and Flow Velocity(US unit)
Unit:L/min
Meter size
(mm)
0.3m/s 1m/s 3m/s 10m/s
2.5 0.08835 0.2945 0.884 2.945
4 0.2262 0.7540 2.262 7.540
6 0.5088 1.6967 5.090 16.967
About establishment environment
Do not store or install the flowmeter:
• Where there is direct sunlight.
• Where excessive vibration or mechanical shock
occurs.
• Where high temperature or high humidity conditions
exist.
• Where corrosive atmospheres exist.
• Places that can be submerged under water.
• Where there is a sloped floor. To put the flowmeter
temporarily on the floor, place it carefully with
something, such as a block, to support it so that the
flowmeter will not topple over.
In areas like the following, there may be the case that
infrared switches do not function correctly. (If these are
unavoidable, use an appropriate cover.)
(1) Where unit (operation panel) is exposed to direct
sunlight, reflection of light onto window pane and
diffused light reflection.
(2) Where smoke and steam may occur.
(3) Where exposed to direct snow, ice or mud.
Ordering Information
1. When ordering the LF470 flowmeters, refer to
Tables 4 to 5 (Specification Code).
An entry must be made for each of the columns in
each of these tables.
2. Fluid characteristics:
(1) Type of fluid to be measured and its characteristics
(2) Fluid temperature
(3) Fluid pressure
(4) Electrical conductivity of the fluid
3. Measuring range
4. I/O function setting
5. Ordering scope:
Flow calibration data: (required or not)
6. Other items
Specifications other than standard items
Consult a Toshiba representative before ordering when
choosing materials of the wetted parts such as lining,
electrodes, and grounding rings.
.