3B Scientific Stirling Engine D - Manual (Page 11)

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• If the Stirling engine fails to keep moving of its
own accord, wait about a minute longer and
push the rotor round again.
8.2 Recording a pV diagram
To record a pV diagram, the following pieces of
equipment are also required:
1 Supplementary set for Stirling engine D U8440455
1 3B NETlog™ unit (230 V, 50/60 Hz) U11300-230
or
1 3B NETlog™ unit (115 V, 50/60 Hz)
U11300-115
1 3B NETlab™ program U11310
1 Relative pressure sensor, ±100 hPa U11321
1 Displacement sensor U11371
1 DC power supply, 15 V, 1.5 A (230 V, 50/60 Hz)
U8521121-230
or
1 DC power supply, 15 V, 1.5 A (115 V, 50/60 Hz)
U8521121-115
• Connect the relative pressure sensor to the
hose nozzle using silicone tubing.
• Attach the base plate to the stand using the
knurled screw.
• Screw the stem with the magnetic base into the
displacement sensor and place it on the base
plate.
• Loosen the screw on the displacement sensor’s
pulley. Wind a thread once around the pulley
and lead it out of the recess placing a loop
around the screw. Use the screw to fix the
thread in place (see Fig. 8).
• Attach one end of the thread to the hook of the
connector rod and suspend a weight from the
other end.
• Use the suction pad to attach a second thread
to the base plate. Thread this over the groove
in the eccentric and use the other weight as a
load on the free end.
• This load ensures that the pV diagram comes
out better.
Fig. 8 Schematic illustration of how the thread is wound
around the pulley of the displacement sensor (U11371)
• Connect the power supply to the heater plate
and set the voltage up to 12 V (1.5 A approx.).
• Connect both sensors to the 3B NETlog™ inter-
face.
• Run the software on a computer.
• After the Stirling engine has heated up, start it
running by pushing the rotor in a clockwise di-
rection.
• Start a measurement using the software and
evaluate the data.