Teledyne 4220 - Manual (Page 90)

4220 Flow Meter
Section 3 Installation
3-8
3.3.2 Location of the Flow
Meter
Because the flow meter uses a submerged probe for level mea-
surement, you do not have to install it directly above the primary
measuring device, or even particularly close to the flow stream.
You can install the flow meter in a convenient, protected location
and route the submerged probe cable to the place where the level
sensor is mounted.
For example, you can install the flow meter above ground for pro-
tection and easy accessibility, and then you only need to enter the
manhole once, for submerged probe installation and calibration
You will need to mount the unit within 25 feet (7.6 m), if you
connect the probe directly to the flow meter.
You can extend the distance to 50 feet (15.3 m) if you use the
optional 25 Foot Extension Cable. Using the optional 50 Foot
Extension Cable lets you increase the distance to 75 feet (22.8
m).
For distances up to 1,000 feet, (304.8 m) use the optional
Quick-Disconnect Box. Distances greater than 1,000 feet are not
recommended. Details on the extension cables and Quick-Dis-
connect Box can be found in Section 5 of this section.
3.3.3 Mounting the 4220 The 4220 does not have any special requirements for mounting.
You can locate it on any relatively flat surface either horizontally,
supported by the two mounting pads and the stainless steel
mounting bracket, or vertically, supported by the two plastic rails
on the bottom of the case.
You can also panel-mount the flow meter, using the mounting
bracket on the top rear of the case or suspend it from a ladder
rung using the optional suspension bracket. To use the bracket,
the carrying handle should first be installed on the flow meter as
described above. Then slip the handle through the suspension
bracket.
3.3.4 Suspension Above the
Flow Stream
If you suspend the flow meter above the flow stream and there is
any possibility of accidental submersion, attach several feet of
vinyl tubing to the open vent on the end of the external desiccant
cartridge. You should route this tubing to a place higher than the
maximum possible level of the flow stream. This will prevent any
water from entering the vent tube for the submerged probe in
case of accidental submersion of the flow meter. Vinyl tubing can
be purchased locally or from Teledyne Isco.
3.4 Quick-Disconnect Box If you use the Quick-Disconnect Box to extend the distance
between the flow meter and the probe, you should attach the
vinyl tubing to the desiccator cartridge vent on the Quick-Dis-
connect Box.
You can install the flow meter as far as 1,000 feet from the sub-
merged probe if you use the Quick-Disconnect Box. Otherwise,
the flow meter must be located within 75 feet of the submerged
probe, as this is the maximum length of cable available to
connect the submerged probe to the flow meter (25 feet supplied
with the submerged probe plus 50 feet maximum with one of the