Instruction and Operation Manual
X-CM-QmBS-eng
Part Number: 541B052AHG
June, 2008
Section 2 Installing the Sensor
QmBS Sensor / QTA Transmitters
2-2
2.3.2 Distance from Transmitter
The maximum cable length between the sensor and the transmitter is 1000 ft (300 m).
If you are installing the QmBS sensor for use in an MVD
TM
Direct Connect
TM
installation:
•
The maximum cable length between the sensor and the direct host is 1000 ft (300 m).
•
The maximum cable length between the sensor and the power supply depends on the wire
size, as shown in Table 2-1. The wire must be sized to provide a minimum of 15 V at the
sensor. See the discussion in Section 5.4.1.
Brooks supplies 4-wire cable to connect the sensor to the transmitter or remote host. The cable is
fitted with a Eurofast
®
connector for connection to the sensor. Cable can be ordered in lengths
ranging from 6.5 ft (2 m) to 500 ft (150 m). For longer cable lengths, contact the factory.
2.3.3 Pipe Run
Brooks sensors do not require a straight run of pipe upstream or downstream.
2.3.4 Shutoff Valve
After the sensor and transmitter have been installed, you must perform the zeroing procedure. During
the zeroing procedure, flow through the sensor must be halted and the sensor tubes must be
completely full of process fluid. A shutoff valve, downstream from the sensor, is recommended to halt
flow during the zeroing procedure. For more information about zeroing, ( refer to your specific
transmitter instruction manual.)
2.4 Orienting the Sensor
The sensor will function properly in any orientation if the sensor tubes remain filled with process fluid.
2.4.1 Flow Direction Arrow
The sensor has a flow direction arrow to help you configure the transmitter for flow direction. Install the
sensor so that the flow direction arrow matches actual process flow for best performance.
2.4.2 Vertical Pipeline
If the sensor is installed in a vertical pipeline, liquids and slurries should flow upward through the
sensor. Gases may flow upward or downward.
2.5 Mounting the Sensor
Use your common practices to minimize torque and bending load on process connections. Figure 2-1
illustrates how to mount the sensor. Refer to page A-3 for the QmBS sensor dimensions
Table 2-1 Power Supply Wire Size and Cable Length – MVD Direct Connect Installations
Wire size
Maximum length
22 AWG (0.35 mm
2
)
300 ft (90 m)
20 AWG (0.5 mm
2
)
500 ft (150 m)
18 AWG (0.8 mm
2
)
500 ft (150 m)
