UVP
TRANSDUCERS
The
transducer is the connecting device between the Ultrasonic Velocity Profiler
(UVP) and the test medium, emitting acoustic pulses and then literally
'listening' to the flow echo. It constitutes a fundamental element in
the measurement process, which on its quality depends. It follows that
Met-Flow attaches a major importance to the development and the manufacturing
quality of transducers to provide the most accurate and sensitive device.
Specifications about transducer cables...
Transducer models list...
Go to...
UVP-DUO line
UVP-XW line
Software description
PDF technical flyer: UVP transducer (71 kB)
TRANSDUCERS
All Met-Flow
transducers are custom-designed and optimised for maximum UVP performance.
Excitation
Met-Flow transducers are connected to the UVP Monitor by a standard BNC
connector. Maximum operational peak-to-peak voltage is 200V, maximum applicable
DC voltage is 500V. Electrical input impedance of all transducers is close
to 50 Ohm.
Efficiency
Transducer electric-to-acoustic efficiency is approximately 40-50%. The
losses are mainly due to absorption in the backing necessary to generate
short ultrasound pulse (minimum 2 cycles of a wavelength) required by
UVP technique.
Material
Transducer casing material is Delrin, a plastics material resistant to
most of common chemicals. Nevertheless , Met- Flow only guarantees transducer
resistance to water and mercury. In case of other chemicals, please consult
Met-Flow.
Frequency range
The following transducer centre working frequencies are available: 0.5,
1, 2, 4, 8 MHz.
Generally, lower frequencies are used in large scale applications for
their good propagation abilities, while higher frequencies are used for
small-scale flows for which they offer good spatial resolution due to
their short wavelength.
Standard line
Standard Met-Flow transducers are plane-wave type, with a flat active
element. These transducers for 'normal' temperature range up to 60°C
temperature (in the immediate vicinity of the transducer) are named by
letters 'TN'.
High temperature lines
Similar transducers are available for two ranges of extended temperatures
up to 150 °C or 250°C. They are named by the letters 'TH' and
'TV' respectively. These transducers have special casing for good thermal
isolation and special inner elements to resist thermal constraint. TH
transducers are available with their standard casing or with a special
stainless steel casing with resin slots.
Focused line
Spherical focusing transducers ('TF' denomination) are custom-made on
request. The focusing effect is given by a spherical active element. More
information on TF transducers is available on request.
Casing length
The transducer casing diameter is derived from the active element diameter.
The default casing length is 60 mm, but other lengths (minimum 36,5 mm)
can be manufactured on request with no additional cost. Other specific
developments can be considered; feel free to contact us for further information.
top
TRANSDUCER
CABLES
Met-Flow
transducer cables can be considered as a standard 50 Ohm coaxial cable
(Type KX 15 for normal temperature or KX 18 for extended), with an attenuation
of under 0,1 dB/m for a 8 MHz signal. The attenuation decreases with frequency.
Default cable length is 4 m, but can be specified longer (up to 10 m)
or shorter when ordering transducer. For cables longer than 4 meters,
small surcharge may apply. In any case the cable is firmly fixed to the
transducer and cannot be extended.
A reasonable extension of transducer cable using an additional standard
50 Ohm coaxial extension cable with BNC connectors should not be critical
from attenuation point of view.
However, in strong electromagnetic interference (EMI) environment, overall
cable length has to be minimised. This is why Met-Flow garantees reliable
functioning of its transducers up to 4 meter cable length only.
STANDARD MET-FLOW TRANSDUCERS
Symbols used in transducer denominations:
TN transducer for temperatures up to 60°C
TH transducer for high temperatures (up to 150°C)
TV transducer for very high temperatures (up to 250°C)
TF focused (spherical) transducers
1st digit frequency
2nd digit active diameter in mm
3rd digit exterior diameter in mm
| PLAIN-WAVE TRANSDUCERS | ||||||
|
Transducer
type
|
Centre
frequency [MHz]
|
Active
diameter [mm]
|
Overall
diameter[mm]
|
Overall
length [mm]
|
Near-field
distance [mm]
|
Divergence
half-angle [deg]
|
| Normal temperature range (up to 60°C) | ||||||
| TN05-19-23 |
0,5
|
19
|
23
|
60
|
30,5
|
4,6
|
| TN1-13-16 |
1
|
13
|
16
|
60
|
28,5
|
3,4
|
| TN2-10-13 |
2
|
10
|
13
|
60
|
33,7
|
2,2
|
| TN4-5-8 |
4
|
5
|
8
|
60
|
16,9
|
2,2
|
| TN8-2.5-8 |
8
|
2,5
|
8
|
60
|
8,43
|
2,2
|
| High temperature range (up to 150°C) | ||||||
| TH4-5-8 |
4
|
5
|
8
|
60
|
16,9
|
2,2
|
| Very high temperature range (up to 250°C) | ||||||
| TV4-5-8 |
4
|
5
|
8
|
60
|
19,9
|
2,2
|
| FOCUSED TRANSDUCERS | ||||||
| Transducer type |
Centre
frequency [MHz]
|
Active
diameter [mm]
|
Overall
diameter [mm]
|
Overall
length [mm]
|
Real
focus point minimum [mm]
|
Natural
focus point N [mm]
|
| TF05-19-23 |
0,5
|
19
|
23
|
60
|
>20,3
|
30,5
|
| TF1-13-16 |
1
|
13
|
16
|
60
|
>17,4
|
28,5
|
| TF2-10-13 |
2
|
10
|
13
|
60
|
>15,2
|
33,7
|
| TF4-5-8 |
4
|
5
|
8
|
60
|
>10,8
|
16,8
|
| TF8-2,5-8 |
8
|
2,5
|
8
|
60
|
>6,0
|
8.4
|
|
Note:
Focused transducers can be ordered with focus point from listed
minimum length up. |
||||||
