UVP-XW
series
top
1.
Common features
The features common
to all models in the UVP-XW line are:
- Multiple basic
frequencies (2, 4, 8 MHz, 1, 2, 4 MHz, and 0.5, 1, 2 MHz - on request). This
allows greater flexibility in the allowed settings for maximum velocity and
maximum depth.
- Fine increments
of starting depth, maximum depth, channel distance, RF gain control etc.
- Doubling of
the maximum measurable velocity by eliminating sign detection.
- An algorithm
for fast Doppler shift frequency detection.
- More precise
time resolution and sampling time.
- Direct call
to the review software.
- An external
screen option, in order to simultaneously use a second monitor.
- An integrated
Pentium PC.
- Windows NT operating
system.
- Enhanced user-friendly
interface for the UVP and Review software, which have been rewritten to run
as true Windows NT programs. In addition, the review software can run under
Windows 95/98.
- The unit can
be used as a normal PC when the UVP is not in use.
The present configuration
of the internal PC is:
- 266 MHz Pentium
processor
- 128 Mbytes of
RAM (expandable to 256 MB)
- 10 GB hard drive
- 1.44 MB floppy
drive
- Color TFT 8.4
inch liquid crystal display
- VGA connector
to simultaneously drive a second monitor
- Mouse
- Two serial ports
- Parallel port
- Network port
(Ethernet, 100 base T (new))
top
2. Models with
integrated multiplexer
In applications
where it is desired to obtain a spatial mapping of the flow characteristics
(flow mapping), the UVP-XW with an integrated multiplexer is the ideal solution.
In these units both the multiplexer and its controller are integrated into the
UVP. Using the supplied software, any of the channels can be selected at random
and in any combination. As a result, several previous time consuming and experience-requiring
tasks (selecting the order in which the transducers are switched, preparing
the timing sequence, etc) are easily accomplished. The sequence and timing of
multiplexer channels are controlled from UVP-XW software.
The multiplexer
comes with 20 output channels multiplexed by relay circuits.
Note: The basic
selection which a customer commissioning a UVP Monitor must do is to decide
on the ultrasonic frequency range selection (1 - 2 - 4 MHz, or 2 - 4 - 8 MHz,
0.5-1-2 MHz on request), since later change of frequency range basically means
major rebuild of UVP Monitor and is rather expensive. To add multiplexer is
relatively easy.
UVP-XW hardware
description
The UVP is designed
so that it may be transported easily. It consists of the main body, a keyboard,
transducer(s), and cables. The keyboard is integrated into the cover of the
main body. Since all controlling functions are accomplished through software,
UVP does not have any controlling elements.
top
3.
UVP-XW architecture
The internal PC
computer transfers parameter setting and control signals through a control line
directly to the UVP hardware. Signals received from the transducers are first
amplified and filtered. Then they are processed and a velocity profile is computed
in the fast DSP (Digital Signal Processor). The profile is transferred directly
to the PC memory. The architecture frees the internal PC to carry out profile
display and analysis while the next profile is being measured and processed.
It also allows continuous profile acquisition.
Figure - Block diagram of a UVP-XW Monitor
top
4.
UVP window function
Met-Flow has been
granted for its 'window function' the European patent 0201460 (1986), Japanese
patent N° 1 986 965 and US patent N° 4,825,422 (1989). Met-Flow's window
function is an exclusive device and/or system to freely select the distance,
number, width, spacing and combination with each other or groupings of, measuring
points along the US beam axis.
Figure - Illustration of 'measurement window function'
top
5.
Main unit
On the front panel
of the main unit there is a 8.5" color TFT liquid crystal display, a 3.5"
floppy disk drive, and a keyboard connector.
On the back panel of the main unit are connectors for an echo raw signal output
(named 'ECHO'), ultrasound 'pulse repetition frequency trigger signal output'
('PRF'), external trigger input ('EXT TRIG'), window start signal output ('START
GATE'). There are also BNC connectors for the transducers signal ('TRANSDUCER'),
the number of connectors depending on the model. Models with integrated multiplexer
usually have 20 BNC connectors numbered from 1 to 20. Models without multiplexer
have three BNC connectors, one for each ultrasonic frequency. When multiplexer
models work with multiplexer switched off, then the first three connectors correspond
to the three connectors for different ultrasonic frequencies. Connector # 1
corresponds to the lowest frequency.
Warning: The
user should ensure that the connector and transducer are matched appropriately.
Incorrect connecting of wrong-frequency connector could lead, under certain
conditions, to permanent damage to transducer and/or UVP circuitry.
In addition there
are connectors on the back panel for an external display ('VGA'), two 9-pin
serial ports 'COM1', 'COM2' (one for the mouse), a parallel port ('LPT1'), and
an Ethernet BNC port ('NETWORK').
The echo signal output ('ECHO') is used to monitor the ultrasound emission and
received echo. Displaying this signal on an oscilloscope provides information
in the most convenient form for adjusting parameters, transducer settings, etc.
It is particularly helpful in recognising the position of a wall or obstacles
in the flow.
Note: We strongly
recommend that the echo signal be monitored in all investigations. It is the
only reliable way how to make sure that what you measure is not an artefact
caused by false reflection from walls etc.
The ultrasound
pulse trigger signal ('PRF') supplies the timing signal for an ultrasound pulse
emission. This output is usually connected to the external trigger input of
an oscilloscope.
The window start signal ('START GATE') can be monitored together with the echo
signal on the oscilloscope for identifying the starting depth (initial measurement
volume) on the measuring line.
The external trigger ('EXT TRIG') is used to trigger the start of the measurement
of a profile.
The external monitor can be connected to VGA connector as a second display for
the UVP, or when using the machine as an independent PC.
The power line, fuse holder and power connector are fitted on the back panel.
In the following table is an overview of UVP's external connectors and their
functions.
| Connector |
Description |
Explanation |
| ECHO |
Echo
Signal |
BNC
connector to oscilloscope for monitoring a received echo signal. |
| PRF |
Pulse
Trigger Signal |
This
signal supplies the timing for an ultrasound pulse emission. Connect this
output to the external synchronisation input of an oscilloscope. |
| EXT
TRIG |
Trigger |
BNC
connector to an external trigger signal-generating circuit. The trigger
signal defines the start of profile storing. |
| START
GATE |
Window
Gate Signal |
This
signal can be monitored together with the echo signal on an oscilloscope.
Used to identify the starting depth on the measuring line. |
| TRANSDUCERS |
Transducers |
BNC
connectors for the transducers. The basic UVP-XW model has three - labelled
2, 4, and 8 MHz, or 1, 2, and 4 MHz, eventually 0.5, 1 and 2 MHz. Ensure
that the transducer and connector are matched appropriately.The UVP-XW multiplexer
unit has twenty BNC connectors - labelled CH1, CH2,...CH20. |
| COM1 |
Serial
Port |
Mouse |
| COM2 |
Serial
Port |
Free |
| VGA |
External
Display |
For
Multisync color VGA display. |
| LPT1 |
Parallel
port |
The
parallel port may be used for printer output or for other parallel communication.
Please refer to the Windows NT manual for its usage. |
| NETWORK |
Ethernet
port |
The
Ethernet port enables connection to computer network (BNC connector 50 Ohms).
Please refer to the Windows NT manual for network communication protocol
configuration. |
Figure - Backplate of the UVP-XW-PSi with internal multiplexer
top
6. Keyboard
The keyboard forms
the top cover of the main unit, and it can be detached from the main unit by
spring-loaded nipples on the sides. A spiral-wound cable connects the keyboard
to the main unit.
Preparation
for operation
top
7. Frequency
selection
Generally speaking the higher frequency ranges offer a higher spatial resolution
and higher velocity resolution than the lower. Thus high frequency use is ideal
for small geometries with small velocity range. 8 MHz is for instance a frequency
that would be selected to measure a blood flow.
On the other hand the low frequencies allow higher Doppler shift frequency
detection corresponding to larger velocities and larger probing distance. Moreover
they have better propagation abilities through the measured liquid as well as
through walls when non-intrusive probing is required. In return lower frequency
means larger waveform and thus poorer spatial resolution, but because of larger
measurement volume in a higher velocities environment the flux of reflectors
is increased resulting in a higher sensitivity of the related probes.
The following table is gathering the typical measurement limits of each available
frequency in water (sound velocity c = 1'483 m/s), the measurable depth (probing
distance) is then indicative.
|
TYPICAL
MEASUREMENT LIMITS
|
|
|
|
Frequency
|
Spatial
Resolution
|
Measurable
Depth
|
Measurable
Velocity
|
Sampling
Rate
|
|
|
(4
cycles/pulse in water)
|
(range)
|
range
(+/-)
|
resolution
|
(32
repetitions in water)
|
|
[MHz]
|
[mm]
|
[mm]
|
[mm/s]
|
[mm/s]
|
[msec]
|
[Hz]
|
|
0,5
|
5,93
|
100
|
5'498,2
|
43,29
|
4,3
|
231,72
|
|
|
|
3'000
|
183,3
|
1,44
|
129,5
|
7,72
|
|
1
|
2,97
|
100
|
2'749,1
|
21,65
|
4,3
|
231,72
|
|
|
|
3'000
|
91,6
|
0,72
|
129,5
|
7,72
|
|
2
|
1,48
|
100
|
1'374,6
|
10,82
|
4,3
|
231,72
|
|
|
|
1'500
|
91,6
|
0,72
|
64,7
|
15,45
|
|
4
|
0,74
|
100
|
687,3
|
5,41
|
4,3
|
231,72
|
|
|
|
750
|
91,6
|
0,72
|
32,4
|
30,90
|
|
8
|
0,37
|
100
|
343,6
|
2,71
|
4,3
|
231,72
|
|
|
|
750
|
45,8
|
0,36
|
32,4
|
30,90
|
|
|
(channel
width)
|
(maximum
depth)
|
(maximum
velocity)
|
|
|
|
top
8. Power supply
The line voltage
is 117/240V AC, 50/60 Hz (pre-set at the factory to end-user's expected local
voltage). Grounding of the power line is necessary, especially when an external
display or external computer is connected. UVP power consumption is about 50W.
Surges on the power line should be avoided.
Warning: Before
the first powering on the UVP Monitor, check the line voltage on the voltage
selector! Every effort has been made to deliver the UVP Monitor to you with
correct voltage set, but Met-Flow cannot be responsible for any damage on the
UVP Monitor caused by powering the UVP Monitor with wrongly selected power line
voltage.
Note: We recommend
a warm-up time of the UVP hardware of at least one minute after switching on
the UVP Monitor.
top
9.
Transducer
Even though ultrasound
transducers are relatively robust, and electronic filtering of signal in the
UVP eliminates some signal frequencies caused by external sources of vibration,
special care should be paid to transducer mounting. When the transducer is mounted
against a solid surface (e.g., the outside wall of a container), any air gap
between the wall and the top surface of the transducer may prevent or disturb
the propagation of the ultrasound wave, resulting in an unsatisfactory measurement.
To handle such cases some ultrasound jelly is supplied with your UVP, which
provides good coupling between the transducer and the mounting surface. A pea-sized
amount of jelly on the working surface of a transducer will do.
Excessive operating temperature at the transducer may cause its permanent damage.
The nominal operating temperature of the common TN-Series transducer is up to
60°C.
An excessive heating up of a transducer can also be caused by powering of a
transducer not acoustically connected with the measured media (US energy does
not leave the transducer), while simultaneously selecting very long pulse length
and high US emission voltage. Your finger is sufficient to check the temperature.
If you cannot hold your finger on a transducer because it is too hot, UVP use
should be interrupted, and transducer fit improved.
Warning: Always
check the working temperature of transducers which are operated in the air.
Met-Flow is not responsible for damage to transducers caused by excessive heating
of transducer.
top
10.
Floppy drive
The set of measured
velocity profiles can be transferred from the UVP memory to a file on the hard
disk or a (3 ½" 2HD) diskette in the floppy drive. The floppy diskette
should be DOS-formatted prior to use.
top
11.
External multiplexer box
External multiplexer
box (called also Relay box) is connected to UVP monitor with two cables:
- signal cable,
which is a regular 50 Ohm co-axial cable to transmit the measurement signal
- command cable,
which is a multi-wire cable to activate each of multiplexer relays
To make both single-
or multi-transducer measurement, both cables have to be connected, having the
signal cable set on the selected frequency connector for the XW3-PSi line.
Note: For the
multi-transducer measurement in strong EMI environment it is even recommended
to connect the three frequencies with three signal cables (1 command cable and
3 signal cables supplied for the external multiplexer box option).
Figure - External multiplexer box
top
12. Networking
the UVP monitor
The UVP-XW instrument
includes an Ethernet card with a BNC connector, which enables integration of
UVP Monitor into a network. This includes networking with another single computer
with an Ethernet card.
Figure - UVP-XW networking with a single computer and with network
Please note that
any Ethernet card using a BNC connector requires a special "50 Ohm adaptation"
plug at the output, found on the market in the form of a simple BNC T-plug with
a cap at one end.
Figure - Ethernet 50-Ohm impedance matching
