3B SCIENTIFIC PHYSICS U188501 Instructions D'utilisation page 6

•
Slide the coils onto the assembly cylinder and
insert them into the basic unit as shown in
Fig. 2.
•
Take care when doing this to ensure the direc-
tion of the windings of both coils is the same.
The arrows embossed on the coils must point in
the same direction.
•
Tighten the knurled screws an equal amount by
hand. Make sure that the assembly cylinder is
located accurately on the assembly rings.
Fig. 2 Basic unit complete with coils
3.2 Connection to the control console
•
Insert the probe into the chamber in the basic
unit so that it touches the housing (see Fig. 3).
•
Plug the lead from the probe into the socket
"Probe In" on the control console. Take note of
the slot in the connector socket.
•
Connect the coils to the "Coil" output on the
back of the console.
•
Connect the control console with plug-in power
supply via socket "12 VAC/1A".
•
Insert the DPPH sample (orange cap) into the
sample chamber (see Fig. 4).
Fig. 3 Basic unit with probe
Fig. 4 Basic unit with DPPH sample inserted
3.3 Calibration and settings
3.3.1 Use of an oscilloscope
•
Connect the output "SIGNAL OUT" on the control
console to channel 1 of the oscilloscope and the
output "FIELD OUT" to channel 2 (see Fig. 5).
•
Set the oscilloscope as follows:
Channel 1: 2 V DC
Channel 2: 1 V DC
Time base: 5 ms
Trigger from channel 2, filter set to Low Fre-
quency
3.3.2 Use 3B NETlog™
•
Connect the output "SIGNAL OUT" on the control
console to input
and out "FIELD OUT" to input
•
Connect the 3B NETlog™ unit to a computer and
run the 3BNETlab
•
Set up a new data record from the "Measure-
ment lab" menu option and define the following
parameters:
Input A: Field, input mode VDC, Input range 2 V
Input B: Signal, input mode VDC, Input range 2 V
Measuring interval: 500 μs (2 kHz)
•
Click the "Oscilloscope" button and start the
measurement.
An oscilloscope window will open.
•
Set to trigger from input A, select a falling edge
and a positive trigger threshold at about 10 to
20%.
3.4 Experiment procedure
•
Set a frequency of about 50 MHz on the control
console. (since the frequency knob is a 10-turn
potentiometer, it may be necessary to turn it
round several times).
•
Set the sensitivity to where the maximum signal
amplitude is obtained.
2
IN
U on the 3B NETlog™ unit
B
IN
U .
A
TM
software on the computer.