The princi principle ple of the three three acoust acoustic ic sensor sensorss is identi identical cal:: an acoustic signal is transmitted, transmitted, reflected and received back. To receptio reception n of the elapsed elapsed time gives inform information ation about about the the distance distance travelled travelled and thus the distance distance to the reference. reference.
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7.
Application
7.3 7.3.4 7.3.4.2
Levelling Acoustic S ensors Ultrasonic-Single-Tracker
Ultrasonic Sensor For Height Measurement
Due to the small dimensions of the sensor, it is suitable ideal For narrow job sites or road construction with small radii. Ideal for job sites where the exact copy of the reference is required. This includes the paving of two parallel tracks Hot-on-Hot or Hot-on-Cold ore somewhere else where large changes in paving height must be done within a short time (e.g. speed bumps).
The Ultrasonic-Single-Sensor transmits just one sensor signal. Therefore the Reference is copied 1:1 without averaging.
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Application
7.3 7.3.4 7.3.4.3
Levelling Acoustic S ensors Ultrasonic-Multi-Sensor
The Ultrasonic multi-sensor is very versatile. By forming an average value of the multiple signals, it can compensate irregularities in the reference. Besides scanning the ground, the reference can also be a string line or a tensioned tight rope with a minimum Thickness of 2,5 mm.
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Application
7.3 7.3.4 7.3.4.4
Levelling Acoustic S ensors Ground Mode String Mode Niveltronic
Niveltronic
Big-Multiplex-Ski
Ground Mode 3 Sensors active Average is calculated and used
String Mode
5 Sensors active die 2 Signals with the largest deviation will be faded out, the remaining three are used - after calculating an average value
5 Sensors active no averaging of values always the shortest distance to the reference (string) is used as valid signal
e g n ) a R m g m n i 0 k r 5 o 6 W e 0 l 5 b 2 a ( i r a V
c i e n ) i g o k r S n t a l g i R e v B g i N n i k r m m o m m 0 W 0 e 0 5 0 l b 6 1 a i r 0 0 a 5 V 5 2 2 (
Sensing Range
Ground
Big-Multiplex-Ski
50 mm (+25mm/-25mm)
Sensing Range
50 mm (+25mm/-25mm)
String
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7.3 7.3.4 7.3.4.5
Levelling Acoustic S ensors Characteristics of Acoustic Sensors
Since sound waves move at changing environment temperature with different Speed an a compensation of that inconvenient behaviour is required. I.e. the ambient temperature is increasing, the sound waves would move faster and could distort the measurement result. Distance measurement for Temperature Compensation
For the required compensation, the single-sensor has a Metal bracket with a fixed distance to the sensor. The distance is measured continuously. When the time from sending and receiving is changing due to a change in the environment temperature, the signal to the Niveltronic will be corrected.
At the Ultrasonic-Multi-Sensor a sixth sonic signal is working in a similar way. Distance measurement for Temperature Compensation
Info Sound Wave Speed at 0° C = 331 m/sec at 30° C = 349 m/sec
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Application
7.3 7.3.4 7.3.4.6
Levelling Acoustic S ensors Big Multiplex - Ski
Three Ultrasonic-Wide-Range Sensors, each with five sensor cells to form an averaged value for the Niveltronic, be connected to the Big-Multiplex-Ski. Each sensor sends its measurement results to the central unit. By using the average value, the system recognizes elongated bumps and levels them.
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Application
7.3 7.3.4 7.3.4.6
Levelling Acoustic S ensors Big Multiplex - Ski
The expandable rack allows variable ski lengths of 5 m to 13 m
Obstacles outside of an adjustable tolerance will be excluded and omitted while calculating the mean-value (bucket, shuffles, big rocks, ...).
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Application
7.3 7.3.4 7.3.4.6
Levelling Acoustic S ensors Big Multiplex - Ski Sensor Detection
Central Unit of the Big-Multiplex-Ski
Each Sensor station that is used the first time is first identified via LED. In addition sensor configurations or error messages are shown in the LCD display
LCD: Sensor Message LCD: Sensor Assignment LED: Sampling type Selection of Sampling type 2
Call Working Window. The value corresponds to the permissible measurement range of sensors around the calibration point (Value 6 = +/- 3cn) Change (in increments of 1cm between 4,0 and 20,0) or deactivate the range (bigger 20,0 = OFF).
When the Big-Ski has been connected the first time or if the sensor combination has changed, the sensor detection must be acknowledged. The display flashes before confirmation. After confirmation (by pressing any button) is continuously on. Set Value Calibration
The sensors must be calibrated before starting the first time or when fundamental changes in settings took place. When the Set-button is pressed, the calibration is done and SET Appears in the display.
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7.3 7.3.4 7.3.4.6
Levelling Acoustic S ensors Big Multiplex - Ski
Aufbau Big-Multiplex-Ski
1
2
3
P WIRTGEN G R O U P
VÖGELE
1
2
3
Sensor Sockets
Analogue connection cable
Standard CAN Kabel
CAN Cable with 2x 120 R CAN bus resistors Standard CAN Cable Sonic-Ski CAN
Sonic-Ski CAN
Sonic-Ski CAN
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7.3 7.3.4 7.3.4.6
Levelling Acoustic S ensors Big Multiplex - Ski
Installing the Big-Multiplex-Ski
Screed Arm Attachment
End gate Attachment
For scanning within the paving width.
For scanning outside the paving width.
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Application
7.3 7.3.4 7.3.4.6
Levelling Acoustic S ensors Big Multiplex - Ski
Installing the Big-Multiplex-Ski
Screed Arm Attachment
End Gate Attachment
For scanning within the paving w idth.
For scanning outside the paving width.
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Application
7.3 7.3.4 7.3.4.7
Levelling Acoustic S ensors Recommendation for Acoustic Sensors
