Dynasonics DXN Portable Ultrasonic Measurement System - Manual (Page 53)

Transit Page
Site Name 0.00 GPM
03/28/2012
13:24
Meter Adv Cal System Display Site Log I/O
Create Lookup Liner Doppler Fluid Pipe Transit
Required Spacing (in)
Transducer
Transducer Mount
DTTN 1MHz
Z
12.14 12--1/8”
Figure 68: Site/Transit
Transducer [Transducer Type and Frequency] - (Choice)
DTTN 1 MHz Standard Transducers DTTL 0.5 MHz Large Pipe Transducers
DTTH 1 MHz High Temperature Transducers DTTSU 2 MHz Small Pipe Transducers
Table 12: Transducer Types and Frequencies
Transducer transmission frequencies are specific to the type of transducer. In general the DTTL 500 KHz (0.5 MHz) transducers
are used for pipes greater than 24" (600 mm). DTTN and DTTH, 1 MHz transducers, are for intermediate sized pipes between
2" (50 mm) and 2" (600 mm). The DTTSU uses a 2 MHz transmission frequency and is used for pipe sizes between 1/2" (13 mm)
and 2" (50 mm).
Transducer Mount [Transducer Mounting Method] - (Choice)
Selects the mounting pattern for the transducers. The selection of an appropriate mounting pattern is based on pipe and
liquid characteristics.
DXN transit time flow meters can be used with four different transducer types: DTTN, DTTH, DTTL, and DTTSU. The DTTN,
DTTH or DTTL transducer sets consist of two separate sensors that function as both ultrasonic transmitters and receivers.
DTTSU transducers integrate both sensors into one assembly. All transducers require the separation of the transmit/receive
modules be adjusted to the spacing value calculated during the DXN setup. DTTN and DTTL transducers are clamped on the
outside of a closed pipe at a specific distance from each other.
The DTTN and DTTL transducers can be mounted in:
• W-Mount where the sound traverses the pipe four times. This mounting method produces the best relative travel
time values but the weakest signal quality.
• V-Mount where the sound traverses the pipe twice. V-Mount is a compromise between travel time and signal quality.
• Z-Mount where the transducers are mounted on opposite sides of the pipe and the sound crosses the pipe once.
• Z-Mount will yield the best signal quality but the smallest relative travel time.
See Table 2 for transducer mounting mode selection starting points.
Required Spacing – [Transducer Spacing] (Value Calculated by Meter)
NOTE: N
This value is calculated by the firmware after all pipe parameters have been entered.
Installation & Operation Manual
Page 53 February 2013