ADS Environmental Services FlowShark Pulse QR 775004 A1 - Manual (Page 63)

6-18 ADS FlowShark Pulse O&M Manual
The maximum cable length for an LUS air-ultrasonic sensor is 328
feet (100 m). This sensor cable may not be extended.
The signal cable attached to the sensor is not designed for underground burial for an
extended period of time without protection. When burying signal cables in soil,
concrete, or other comparable materials, first run the cable through conduit for
protection. Consider cable removal and replacement when selecting the inner
diameter, bending radius, and layout of protective pipes and hoses.
When extending the sensor cables, please note that the total
resistance of the power supply lines must not exceed:
• 2.100 Ohm for sensors with 30-foot (10-m) fixed cables
• 1.850 Ohm for sensors with 60-foot (20-m) fixed cables
• 1.600 Ohm for sensors with 90-foot (30-m) fixed cables
(Specification corresponds to feed + return wires!)
Longer cable lengths may be used under certain circumstances involving special
cross-sectional cable areas. Please contact ADS for specific guidance.
Do not use common extensions for different installations or a
common signal cable to extend separate depth and flow velocity
sensors.
For sensors with a pressure measurement cell (Types 3K and 4K, the maximum
uninterrupted cable length is 90 feet (30 m). For cable extensions, install a
connection box with a pressure compensation element (Figure 6-23). This pressure
compensation element, available through ADS, must be installed even if the cable of
a sensor with an integrated pressure measurement cell is connected directly to the
transmitter.
Operating sensors with an integrated pressure measurement cell
for a long period without a pressure compensation element may
lead to irreversible damage to the sensor electronics.