Extension Cables - Teledyne 4250 Installation And Operation Manual

3.5 Extension Cables

Figure 3-6 Assembling a Compression Bushing
The 10-foot range and low profile AV sensors are provided with
25 feet of cable. The 30-foot range AV sensor is provided with 50
feet of cable. If these lengths are insufficient, it is possible to
connect an extension cable between the flow meter and the AV
sensor. Teledyne Isco provides a 25-foot extension cable for either
sensor.
The AV sensor extension cables and the AV sensor cable can-
not be cut for any reason, or they will be ruined. The connec-
tors are factory-sealed and neither the cable nor the vent tube
inside can be satisfactorily spliced in the field.
Teledyne Isco does not recommend connecting more than two
extension cables together to exceed the 75-foot limit (100 ft. for
the 30 ft. sensor). Increasing the length of the vent tube
beyond 75 feet slows the response of the pressure transducer,
and this may cause measurement errors. For greater distances
use the Quick-Disconnect Box and a custom-built cable.
The AV sensor uses a differential pressure transducer and two
ultrasonic transducers. The cable connecting the AV sensor to the
flow meter contains a small tube that references the pressure
transducer to atmospheric pressure. This allows a true differ-
ential pressure measurement unaffected by changes in baro-
metric pressure. This tube is vented through the connector into
the cabinet of the 4250. From there, it is vented to the atmo-
sphere through a desiccant cartridge mounted on the side of
either the flow meter or the Quick-Disconnect Box.
4250 Flow Meter
Section 3 Installation
CAUTION
3-11