3B Scientific SW Sensors Set User Manual

SCIENTIFIC

SW Set - Sensors (230 V, 50/60 Hz) 1012850
SW Set - Sensors (115 V, 50/60 Hz) 1012851

Instruction manual

09/13 TL/ALF

®

PHYSICS

1 Dynamic

2 MEC operating electronics

3 Plug-in power supply, 230 V

(for 1012850),
not shown:
Plug-in power supply, 115 V
(for 1012851)

4 HF cable

force sensors

1. Safety instructions

The SW sensors set complies with safety regu­lations for electronic measuring, control and
laboratory instruments as specified in DIN EN
61010 part 1. It is designed for operation in dry
rooms which are suitable for electrical equip­ment.

Safe operation of the equipment can be guaran­teed as long as it is used in accordance with
specifications. Safety is not, however, guaran­teed if the equipment is handled incorrectly or
without due caution.

2. Description

The SW sensors equipment set is intended for
recording and analysing mechanical oscillations
with the help of an oscilloscope. Force sensors

which dynamically detect the force along their
axis are used for this.

The set with the order number 1012851 is de­signed for a mains voltage of 115 V (±10%)
while 1012850 is made for 230 V (±10%).

2.1 Dynamic force sensor

The dynamic force sensors can be attached to
stand rods of 10 mm in diameter or to the SW
cross bar from the SW stand equipment set
(1012849). They operate by means of the piezo­electric effect

A force applied to the hook causes the piezo­crystal to charge up, whereby the charge is pro­portional to the applied force within certain lim­its. The dynamic characteristic is determined by
the finite junction resistance within the piezo­electric material and that of the impedance con­verter in the associated electronics.

1

Dynamic force sensor set-up

A

The sensors are optimally designed to be mounted on
stands assembled from the SW stand equipment set
(1012849). (See instructions for pendulums listed
below.)

In addition, they can be mounted on plates or on
any rods of 10-mm diameter by means of their
knurled screw.

Caution: Dynamic force sensors must not be

subjected to mechanical overloading

• Neither sensor hook may be loaded with

more than 5N in the axial direction and 1 N
in transverse direction.

• Be especially careful with the maximum

loading force when assembling the system
or suspending loops or springs from the
hook.

2.2 MEC electronics board

1a

12V AC

resistance. In addition, the phase difference
between the two signals can also be evaluated
and output. The other inputs on the board are
not used for this purpose.

Phase detector

A phase detector compares the waveforms for
channels A and B in the time domain to deter­mine the difference in phase between them.
Output Δφ
ence Δφ

supplies the actual phase differ-

AB

in the form of a DC voltage between

AB

8 V (∆φ = 0°) and +8 V (∆φ = 180°).

3. Contents

2 Dynamic force sensors
2 HF cables
1 MEC electronics board
1 Plug-in power supply, 12 V AC

4. Technical data

M

f

A

1b

B

C

Δϕ

B

Fig. 1 MEC electronics board

1a Connector for plug-in mains supply

1b A and B inputs for dynamic

1c A and B outputs for dynamic

force sensors

force sensors

1c

1d

1d ΔφAB output for phase detector

Amplifier channels

Amplifier channels A and B on the MEC elec­tronics board are used in conjunction with the
dynamic force sensors. The board converts the
signals from both sensors to make them suitable
for display in an oscilloscope or other display
instrument. The two channels have high internal

Dynamic force sensor

Maximum force
Axial plane: 5 N
Radial plane: 1 N

Lower frequency limit: 0.2 Hz
Connector: 3.5-mm jack plug
Length of cable 0.8 m
Dimensions: 52 x 37 x 26 mm approx.
Weight: 80 g approx.

Electronic board

Power supplied via plug-in mains transformer
Input sockets: 3.5-mm jack sockets
Output sockets: BNC
Amplifier A, B: Output ±8 V,

Ri = 100 MΩ
Ra = 1 kΩ

Phase detector (XOR): Output ±8 V,

Ra = 1 kΩ

Dimensions: 65 x 100 x 40 mm approx.

Plug-in power supply for 1012850

Primary side: 230 V, 50/60 Hz
Secondary side: 12 V AC; 700 mA

Plug-in power supply for 1012851

Primary side: 115 V, 50/60 Hz
Secondary side: 12 V AC; 500 mA
Only power the MEC electronics board from the

supplied 12 V AC mains transformer.

2