1.8 KiB
- Measure of the noise of the Voltage Amplifier
- Measure of the noise induced by the Slip-Ring
- Measure of the noise induced by the slip ring when using a geophone
- Measure of the influence of the AC/DC option on the voltage amplifiers
Measure of the noise of the Voltage Amplifier
- The two inputs (differential) of the voltage amplifier are shunted with 50Ohms
- The AC/DC option of the Voltage amplifier is on AC
- The low pass filter is set to 1hHz
Measure: Second Column
meas3: Ampli OFF meas4: Ampli ON 20dB meas5: Ampli ON 40dB meas6: Ampli ON 60dB meas7: Ampli ON 80dB
Measure of the noise induced by the Slip-Ring
Setup:
- 0V is generated by the DAC of the Speedgoat
- Using a T, one part goes to ADC
- the other part goes to the slip-ring 2 times and then to the ADC
- Gain of the Voltage Amplifier: 80dB, AC, 1kHz
- Everything is OFF
We had some diffuculties to not have a lot of noise on the measurement.
First column: Direct measure Second column: Slip-ring measure
Measurements:
- meas8: Slip-Ring OFF
- meas9: Slip-Ring ON
- meas10: Slip-Ring ON and omega=6rpm
- meas11: Slip-Ring ON and omega=60rpm
Measure of the noise induced by the slip ring when using a geophone
The geophone is located at the sample location The two Voltage amplifiers have the following settings:
- AC
- 60dB
- 1kHz
The signal from the geophone is split into two using a T-BNC. On part goes directly to the voltage amplifier and then to the ADC. The other part goes to the slip-ring=>voltage amplifier=>ADC.
The other two cables that go through the slip ring have 50Ohms resistors at one end, the other end is open circuit.
First column: Direct measure Second column: Slip-ring measure
- meas12: Slip-Ring OFF
- meas13: Slip-Ring ON
Measure of the influence of the AC/DC option on the voltage amplifiers
One geophone is located on the marble. It's signal goes to two voltage amplifiers with a gain of 60dB. On voltage amplifier is on the AC option, the other on the DC option.
First column: AC Second column: DC
- meas14: col-1 = amp1+AC. col-2 = amp2+DC.
- meas15: col-1 = amp1+DC. col-2 = amp2+AC.