Dynasonics 902_903 Series Portable Doppler Ultrasonic Flow Meter - Manual (Page 14)

Rev. 10/08
- 12 - D902/3
Liquid that contains greater than 10,000 PPM (1%) of
30 micron or greater suspended solids or aeration.
The mounting location and straight pipe requirements for
CASE 2 liquid characteristics are the same as those
described in CASE 1. The difference will be in the location
of the transducers on the pipe. As the discontinuities
(suspended solids or aeration) reach a level of
approximately 1% or 10,000 PPM, sound can no longer be
reliably transmitted through the liquid as it has a tendency
to scatter and absorb into the high concentration of
discontinuity. To compensate for this, the D902/3
transducers can be located on the same region of the pipe.
In a horizontal pipe, mount the transducers at 2 o’clock
and 4 o’clock positions. (Assuming 12 o’clock as the top of
the pipe.) See Figure 5.
Liquid that contains fewer than 25 PPM of 30 micron or
larger suspended solids or aeration. Or, liquid that
contains solids or aeration which is smaller than 30
microns.
The transducers will be mounted 1 to 3 pipe diameters
downstream from a 90° elbow. The orientation of the
transducers on the pipe will be 180° apart and facing each
other and 90° out of the plane of the elbow. See Figure 6
on page 13.
PART 2 - TRANSDUCER INSTALLATION
CASE 3:
Figure 5
CASE 2: