Dynasonics TFXP Series Transit Time Ultrasonic Flow Meter Manuel d'utilisateur télécharger pdf (Page 20)

Rev. 5/09 - 2.2 - TFXP

The first step in the installation process is the selection of an

optimum location for the flow measurement to be made. For this to

be done effectively, a basic knowledge of the piping system and its

plumbing are required.

An optimum location is defined as:

• A piping system that is completely full of liquid when

measurements are being taken. The pipe may become

completely empty during a process cycle – which will result in

the error code 0010 (Low Signal Strength) being displayed on

the flow meter while the pipe is empty. Error codes will clear

automatically once the pipe refills with liquid. It is not

recommended to mount the transducers in an area where the

pipe may become partially filled. Partially filled pipes will cause

erroneous and unpredictable operation of the meter.

• A piping system that contains lengths of straight pipe such

as those described in Table 2.1 on page 2.3. The optimum

straight pipe diameter recommendations apply to pipes in both

horizontal and vertical orientation. The straight runs in Table 2.1

apply to liquid velocities that are nominally 7 FPS (2.2 MPS). As

liquid velocity increases above this nominal rate, the requirement

for straight pipe increases proportionally.

• Mount the transducers in an area where they will not be

inadvertently bumped or disturbed during normal operation.

• Avoid installations on downward flowing pipes unless

adequate downstream head pressure is present to overcome

partial filling of or cavitation in the pipe.

1. Mounting Location

PART 2 - TRANSDUCER & RTD INSTALLATION

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Dynasonics TFXP Series Transit Time Ultrasonic Flow Meter Manuel d'utilisateur Page 20