3B Scientific Ultrasonic Motion Sensor User Manual

3B SCIENTIFIC® PHYSICS

Ultrasonic Motion Sensor U11361

Instruction manual

06/09 Hh

1. Safety instructions

When in operation, the ultrasonic motion sensor
customarily generates individually audible packets of
pulses (bursts) which repeat with variable frequency.
When operated in this way the equipment is guaran­teed to be safe.

• In the case of a fault (visible damage to the

equipment, unusual sounding bursts) the
equipment should immediately be turned off.

2. Scope of delivery

1 Ultrasonic motion sensor U11361
1 Stand rod, 120 mm long
1 Stand rod, 60 mm long
1 miniDIN 8-pin connector lead, 1 m long
1 Instruction manual for U11361

Sensor box for measuring movements in one dimen­sion e.g. on an air track or in free fall.

For use in conjunction with a 3B NETlog
unit for making manual measurements or connected
to a computer running 3B NETlab
acquisition of measured data.

The sensor is detected automatically by the 3B NET-

TM

log

unit.

The motion sensor utilises a gold-foil ultrasonic trans­ducer and transmits packets consisting of 16 ultra­sonic pulses (bursts). The ultrasonic sensor will detect
the echo of such signals from a (moving) object (“tar­get”) after a minimal acoustic lag of about 1 ms –
corresponding to a distance to the object of about 15
cm. The exact distance to the object is calculated from
the time between the transmission of a signal and
detection of its echo, along with the speed of sound in
air, which is temperature dependent. For larger dis­tances between sensor and object, the ultrasonic
transducer automatically adapts the repeat frequency
so that it is about 40 Hz for short distances and ap­proximately 5 Hz for distances up to 10 m.

3. Description

4. Function

TM

(U11300)

TM

(U11310) for

1

5. Technical data

7. Sample experiment

Measuring range: 0.15 m –10 m approx.
Resolution: < 5 mm
Accuracy: ± 1 %
Sensor type: Electrostatic 50 kHz -

transducer
Angle of sensor

wedge opening: 15° @ - 6 dB
Burst repeat frequency: 40 Hz to 5 Hz,

automatically adapted
according to the distance
from the object

Uniform acceleration followed by change
of direction

Required equipment:
1 3B NETlog
1 3B NETlab
1 Ultrasonic motion sensor U11361
1 Universal clamp U13255
1 Air track, 1.6 m U40405
1 Glider 450 g, blue U40422
1 Air-flow generator U15425
1 Conical reflector U40462

• Set up the experiment as shown in Fig. 1. Also

5. Operation

• Screw the stand rod into the M6 nut provided.

• Plug the miniDIN cable into the miniDIN socket

and connect up the 3B NETlog

• Attach the motion sensor mechanically to the

TM

unit.

• Attach the motion sensor using a universal

• Attach the stopper with the pulley to the other

experiment set-up, e.g. in front of an air track,
under a free-falling body or in the path of a vi­brating pendulum bob.

• Turn on the 3B NETlog

TM

unit and wait for it to

• Lower the track by adjusting the height of its

detect the sensor.

• Carry out measurements and evaluate them.

• Connect the sensor by means of its miniDIN

6. Applications

Position, speed and acceleration of moving objects.

• Wait for the 3B NETlog

• Attach a conical reflector U40462 to the glider

Movements in the range of the sensor.
Detecting simple harmonic motion of a weight on a

• Start measuring, starting with the rider moving

spring.
Measuring the period of an oscillating body.

• Open the experiment template for “speed meas-

Objects moving up and down.
The bouncing of a ball.

• Carry out the experiment and evaluate the re-

TM

unit U11300

TM

program U11310

take note of the instructions for the air track.

clamp to the rubber-band launcher on the air­inlet side of the air track, see detailed photo­graph, Fig. 2.

end of the air track. Make sure that the stopper’s
spring buffer is facing along the track.

feet so that the rider moves under its own
weight towards the right-hand end of the track.

connector lead to analog input A or B on the 3B

TM

NETlog

unit.

TM

unit to detect the sen-

sor.

U40422 and turn on the air track.

away from the air inlet end of the track.

urement on an air track” in 3B NETlab

TM

, which
includes all the necessary settings for evaluating
the measurements.

sults. See Fig. 3.

2