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INTRODUCTION

This document explains how to install small pipe transit time 

ultrasonic 

integral

 transducers and transducers with 

remote 

mounting

. The transducers can be installed vertically  

or horizontally. 
The transducers have integrated transmitter and receiver 

elements that eliminate the requirement for spacing 

measurement and alignment.

PRE-INSTALLATION 

REQUIREMENTS

Program the Meter

Before the flow meter will be operational, you must select the 

optimum transmission mode, enter the site information, and 

enter the fluid and pipe properties into the ultrasonic flow 

meter. For detailed instructions, see the user manual for your 

flow meter.

Select a Pipe Location for the Transducers

Select a location for the transducers on a section of pipe that 

has at least 10 pipe diameters upstream of the transducers 

and 5 pipe diameters downstream. See 

“Figure 2: Piping 

configuration and transducer positioning” on page 2

.

For example, if a 2 in. pipe is being measured, the minimum 

upstream pipe in front of the transducer should be 20 in. 

and the minimum downstream pipe behind the transducer 

should be at least 10 in. 
Pipe runs shorter than the minimums may sometimes be 

used with reduced accuracy. There is no way to determine 

how much accuracy is sacrificed without doing  

in-field testing. 
For installations where the 10/5 pipe diameters rule cannot 

be followed, divide the total length of available straight pipe 

into thirds and mount the rail with 2/3 of the pipe upstream 

and 1/3 of the pipe downstream. 
A full pipe is absolutely essential for making accurate flow 

measurements. The flow meter cannot determine if the pipe 

is full or not. If the pipe is partially full, the meter will  

over-report the amount of flow by the percentage of the pipe 

that is not filled with liquid or may not detect any flow. 

Install the mounting system in an area where the transducers 

will not be inadvertently bumped or disturbed.
Avoid installations on downward flowing pipes unless 

adequate downstream head pressure is present to overcome 

partial filling of—or cavitation in—the pipe.

YES

45°

45°

YES

45°

45°

Top of

Pipe

45°

45°

YES

YES

45°

45°

Top of

Pipe

U-Bolt

Split Housing

Figure 1:  Transducer positioning

Transducers

Small Pipe, Fixed Size Transit Time Ultrasonic Transducers

IND-UM-02649-EN-05 (March 2021)

Installation Guide

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