Add data analysis of 03/05

huddle-test-geophones/readme.org

@@ -1,9 +0,0 @@
-* TODO [#B] Find the documentation of the amplifier to know the order of the filters
-* TODO [#A] Shake a little bit the geophones to see if we have better measurements on X and Y axis
-* Measurements
-
-| Filename     | Description |
-|--------------+-------------|
-| data_001.mat | Z axis      |
-| data_002.mat | East        |
-| data_003.mat | North       |

slip-ring-test/index.org

@@ -1,4 +1,4 @@
-#+TITLE:Effect of the rotation of the Slip-Ring
+#+TITLE: Measurements
 :DRAWER:
 #+STARTUP: overview
 
@@ -18,7 +18,22 @@
 #+PROPERTY: header-args:matlab+ :output-dir figs
 :END:
 
-* Measurement Description
+* Effect of the rotation of the Slip-Ring
+  :PROPERTIES:
+  :header-args:matlab+: :tangle meas_effect_sr.m
+  :header-args:matlab+: :comments org :mkdirp yes
+  :END:
+
+#+begin_src bash :exports none :results none
+  zip data/meas_effect_sr \
+      mat/data_001.mat \
+      mat/data_002.mat \
+      meas_effect_sr.m
+#+end_src
+
+The data and matlab files are accessible [[file:data/meas_effect_sr.zip][here]].
+
+** Measurement Description
 Random Signal is generated by one DAC of the SpeedGoat.
 
 The signal going out of the DAC is split into two:
@@ -42,19 +57,19 @@ The goal is to determine is the signal is altered when the spindle is rotating.
 
 Here, the rotation speed of the Slip-Ring is set to 1rpm.
 
-* Matlab Init                                               :noexport:ignore:
+** Matlab Init                                              :noexport:ignore:
 #+begin_src matlab :exports none :results silent :noweb yes
   <<matlab-init>>
 #+end_src
 
-* Load data
+** Load data
 We load the data of the z axis of two geophones.
 #+begin_src matlab :results none
   sr_off = load('mat/data_001.mat', 't', 'x1', 'x2');
   sr_on  = load('mat/data_002.mat', 't', 'x1', 'x2');
 #+end_src
 
-* Analysis
+** Analysis
 Let's first look at the signal produced by the DAC (figure [[fig:random_signal]]).
 
 #+begin_src matlab :results none
@@ -122,7 +137,7 @@ We now look at the difference between the signal directly measured by the ADC an
   set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log');
   xlabel('Frequency [Hz]'); ylabel('PSD $\left[\frac{V}{\sqrt{Hz}}\right]$');
   legend('Location', 'northeast');
-  xlim([1, 500]);
+  xlim([1, 500]); ylim([1e-5, 1e-3])
 #+end_src
 
 #+NAME: fig:psd_noise
@@ -136,9 +151,587 @@ We now look at the difference between the signal directly measured by the ADC an
 #+RESULTS: fig:psd_noise
 [[file:figs/psd_noise.png]]
 
-* Conclusion
+** Conclusion
 #+begin_note
 *Remaining questions*:
 - Should the measurement be redone using voltage amplifiers?
 - Use higher rotation speed and measure for longer periods (to have multiple revolutions) ?
 #+end_note
+* Measure of the noise of the Voltage Amplifier
+  :PROPERTIES:
+  :header-args:matlab+: :tangle meas_volt_amp.m
+  :header-args:matlab+: :comments org :mkdirp yes
+  :END:
+
+#+begin_src bash :exports none :results none
+  zip data/meas_volt_amp \
+      mat/data_003.mat \
+      mat/data_004.mat \
+      mat/data_005.mat \
+      mat/data_006.mat \
+      meas_volt_amp.m
+#+end_src
+
+The data and matlab files are accessible [[file:data/meas_volt_amp.zip][here]].
+
+** Measurement Description
+*Goal*:
+- Determine the Voltage Amplifier noise
+
+*Setup*:
+- 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
+- We measure the output of the voltage amplifier with a 16bits ADC of the Speedgoat
+
+*Measurements*:
+- =data_003=: Ampli OFF
+- =data_004=: Ampli ON set to 20dB
+- =data_005=: Ampli ON set to 40dB
+- =data_006=: Ampli ON set to 60dB
+
+** Matlab Init                                              :noexport:ignore:
+#+begin_src matlab :exports none :results silent :noweb yes
+  <<matlab-init>>
+#+end_src
+
+** Load data
+#+begin_src matlab :results none
+  amp_off = load('mat/data_003.mat', 'data'); amp_off = amp_off.data(:, [1,3]);
+  amp_20d = load('mat/data_004.mat', 'data'); amp_20d = amp_20d.data(:, [1,3]);
+  amp_40d = load('mat/data_005.mat', 'data'); amp_40d = amp_40d.data(:, [1,3]);
+  amp_60d = load('mat/data_006.mat', 'data'); amp_60d = amp_60d.data(:, [1,3]);
+#+end_src
+
+** Time Domain
+The time domain signals are shown on figure [[fig:ampli_noise_time]].
+
+#+begin_src matlab :results none :exports none
+  figure;
+  hold on;
+  plot(amp_off(:, 2), amp_off(:, 1), 'DisplayName', 'OFF');
+  plot(amp_20d(:, 2), amp_20d(:, 1), 'DisplayName', '20dB');
+  plot(amp_40d(:, 2), amp_40d(:, 1), 'DisplayName', '40dB');
+  plot(amp_60d(:, 2), amp_60d(:, 1), 'DisplayName', '60dB');
+  hold off;
+  legend('Location', 'northeast');
+  xlabel('Time [s]');
+  ylabel('Voltage [V]');
+#+end_src
+
+#+NAME: fig:ampli_noise_time
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/ampli_noise_time.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:ampli_noise_time
+#+CAPTION: Output of the amplifier
+#+RESULTS: fig:ampli_noise_time
+[[file:figs/ampli_noise_time.png]]
+
+** Frequency Domain
+We first compute some parameters that will be used for the PSD computation.
+#+begin_src matlab :results none
+  dt = amp_off(2, 2)-amp_off(1, 2);
+
+  Fs = 1/dt; % [Hz]
+
+  win = hanning(ceil(10*Fs));
+#+end_src
+
+Then we compute the Power Spectral Density using =pwelch= function.
+#+begin_src matlab :results none
+  [pxoff, f] = pwelch(amp_off(:,1), win, [], [], Fs);
+  [px20d, ~] = pwelch(amp_20d(:,1), win, [], [], Fs);
+  [px40d, ~] = pwelch(amp_40d(:,1), win, [], [], Fs);
+  [px60d, ~] = pwelch(amp_60d(:,1), win, [], [], Fs);
+#+end_src
+
+We compute the theoretical ADC noise.
+#+begin_src matlab :results none
+  q = 20/2^16; % quantization
+  Sq = q^2/12/1000; % PSD of the ADC noise
+#+end_src
+
+Finally, the ASD is shown on figure [[fig:ampli_noise_psd]].
+#+begin_src matlab :results none :exports none
+  figure;
+  hold on;
+  plot(f, sqrt(pxoff), 'DisplayName', 'OFF');
+  plot(f, sqrt(px20d), 'DisplayName', '20dB');
+  plot(f, sqrt(px40d), 'DisplayName', '40dB');
+  plot(f, sqrt(px60d), 'DisplayName', '60dB');
+  plot([0.1, 500], [sqrt(Sq), sqrt(Sq)], 'k--');
+  hold off;
+  set(gca, 'xscale', 'log');
+  set(gca, 'yscale', 'log');
+  xlabel('Frequency [Hz]'); ylabel('ASD of the measured Voltage $\left[\frac{V}{\sqrt{Hz}}\right]$')
+  legend('Location', 'northeast');
+  xlim([0.1, 500]);
+#+end_src
+
+#+NAME: fig:ampli_noise_psd
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/ampli_noise_psd.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:ampli_noise_psd
+#+CAPTION: Amplitude Spectral Density of the measured voltage at the output of the voltage amplifier
+#+RESULTS: fig:ampli_noise_psd
+[[file:figs/ampli_noise_psd.png]]
+
+** Conclusion
+#+begin_important
+  Noise induced by the voltage amplifiers is not a limiting factor.
+#+end_important
+
+* Measure of the noise induced by the Slip-Ring
+  :PROPERTIES:
+  :header-args:matlab+: :tangle meas_slip_ring.m
+  :header-args:matlab+: :comments org :mkdirp yes
+  :END:
+
+#+begin_src bash :exports none :results none
+  zip data/meas_slip_ring \
+      mat/data_008.mat \
+      mat/data_009.mat \
+      mat/data_010.mat \
+      mat/data_011.mat \
+      meas_slip_ring.m
+#+end_src
+
+The data and matlab files are accessible [[file:data/meas_slip_ring.zip][here]].
+
+** Measurement Description
+*Goal*:
+- Determine the noise induced by the slip-ring
+
+*Setup*:
+- 0V is generated by the DAC of the Speedgoat
+- Using a T, one part goes directly to the ADC
+- The other part goes to the slip-ring 2 times and then to the ADC
+- The parameters of the Voltage Amplifier are: 80dB, AC, 1kHz
+- Every stage of the station is OFF
+
+First column: Direct measure
+Second column: Slip-ring measure
+
+
+*Measurements*:
+- =data_008=: Slip-Ring OFF
+- =data_009=: Slip-Ring ON
+- =data_010=: Slip-Ring ON and omega=6rpm
+- =data_011=: Slip-Ring ON and omega=60rpm
+
+** Matlab Init                                              :noexport:ignore:
+#+begin_src matlab :exports none :results silent :noweb yes
+  <<matlab-init>>
+#+end_src
+
+** Load data
+We load the data of the z axis of two geophones.
+#+begin_src matlab :results none
+  sr_off = load('mat/data_008.mat', 'data'); sr_off = sr_off.data;
+  sr_on = load('mat/data_009.mat', 'data'); sr_on  = sr_on.data;
+  sr_6r = load('mat/data_010.mat', 'data'); sr_6r  = sr_6r.data;
+  sr_60r = load('mat/data_011.mat', 'data'); sr_60r = sr_60r.data;
+#+end_src
+
+** Time Domain
+We plot the time domain data for the direct measurement (figure [[fig:sr_direct_time]]) and for the signal going through the slip-ring (figure [[fig:sr_slipring_time]]);
+
+#+begin_src matlab :results none :exports none
+  figure;
+  hold on;
+  plot(sr_60r(:, 3), sr_60r(:, 1), 'DisplayName', '60rpm');
+  plot(sr_6r(:, 3),  sr_6r(:, 1),  'DisplayName', '6rpm');
+  plot(sr_on(:, 3),  sr_on(:, 1),  'DisplayName', 'ON');
+  plot(sr_off(:, 3), sr_off(:, 1), 'DisplayName', 'OFF');
+  hold off;
+  xlabel('Time [s]'); ylabel('Voltage [V]');
+  legend('Location', 'northeast');
+#+end_src
+
+#+NAME: fig:sr_direct_time
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/sr_direct_time.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:sr_direct_time
+#+CAPTION: Direct measurement
+#+RESULTS: fig:sr_direct_time
+[[file:figs/sr_direct_time.png]]
+
+
+#+begin_src matlab :results none :exports none
+  figure;
+  hold on;
+  plot(sr_60r(:, 3), sr_60r(:, 2), 'DisplayName', '60rpm');
+  plot(sr_6r(:, 3),  sr_6r(:, 2),  'DisplayName', '6rpm');
+  plot(sr_on(:, 3),  sr_on(:, 2),  'DisplayName', 'ON');
+  plot(sr_off(:, 3), sr_off(:, 2), 'DisplayName', 'OFF');
+  hold off;
+  xlabel('Time [s]'); ylabel('Voltage [V]');
+  legend('Location', 'northeast');
+#+end_src
+
+#+NAME: fig:sr_slipring_time
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/sr_slipring_time.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:sr_slipring_time
+#+CAPTION: Measurement of the signal going through the Slip-Ring
+#+RESULTS: fig:sr_slipring_time
+[[file:figs/sr_slipring_time.png]]
+
+** Frequency Domain
+We first compute some parameters that will be used for the PSD computation.
+#+begin_src matlab :results none
+  dt = sr_off(2, 3)-sr_off(1, 3);
+
+  Fs = 1/dt; % [Hz]
+
+  win = hanning(ceil(10*Fs));
+#+end_src
+
+Then we compute the Power Spectral Density using =pwelch= function.
+#+begin_src matlab :results none
+  [pxdir, f] = pwelch(sr_off(:, 1), win, [], [], Fs);
+  [pxoff, ~] = pwelch(sr_off(:, 2), win, [], [], Fs);
+  [pxon,  ~] = pwelch(sr_on(:, 2),  win, [], [], Fs);
+  [px6r,  ~] = pwelch(sr_6r(:, 2),  win, [], [], Fs);
+  [px60r, ~] = pwelch(sr_60r(:, 2), win, [], [], Fs);
+#+end_src
+
+And we plot the ASD of the measured signals (figure [[fig:sr_psd_compare]]);
+
+#+begin_src matlab :results none
+  figure;
+  hold on;
+  plot(f, sqrt(pxoff), 'DisplayName', 'OFF');
+  plot(f, sqrt(pxon),  'DisplayName', 'ON');
+  plot(f, sqrt(px6r),  'DisplayName', '6rpm');
+  plot(f, sqrt(px60r), 'DisplayName', '60rpm');
+  plot(f, sqrt(pxdir), 'k-', 'DisplayName', 'Direct');
+  hold off;
+  set(gca, 'xscale', 'log');
+  set(gca, 'yscale', 'log');
+  xlabel('Frequency [Hz]'); ylabel('ASD of the measured Voltage $\left[\frac{V}{\sqrt{Hz}}\right]$')
+  legend('Location', 'northeast');
+  xlim([0.1, 500]);
+#+end_src
+
+#+NAME: fig:sr_psd_compare
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/sr_psd_compare.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:sr_psd_compare
+#+CAPTION: Comparison of the ASD of the measured signals when the slip-ring is ON, OFF and turning
+#+RESULTS: fig:sr_psd_compare
+[[file:figs/sr_psd_compare.png]]
+
+** Conclusion
+#+begin_important
+
+#+end_important
+
+* Measure of the noise induced by the slip ring when using a geophone
+  :PROPERTIES:
+  :header-args:matlab+: :tangle meas_sr_geophone.m
+  :header-args:matlab+: :comments org :mkdirp yes
+  :END:
+
+#+begin_src bash :exports none :results none
+  zip data/meas_sr_geophone \
+      mat/data_012.mat \
+      mat/data_013.mat \
+      meas_sr_geophone.m
+#+end_src
+
+The data and matlab files are accessible [[file:data/meas_sr_geophone.zip][here]].
+
+** Measurement Description
+*Goal*:
+- Determine if the noise induced by the slip-ring is a limiting factor when measuring the signal coming from a geophone
+
+*Setup*:
+- 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:
+  - One part goes directly to the voltage amplifier and then to the ADC.
+  - The other part goes to the slip-ring=>voltage amplifier=>ADC.
+
+First column: Direct measure
+Second column: Slip-ring measure
+
+*Measurements*:
+- =data_012=: Slip-Ring OFF
+- =data_013=: Slip-Ring ON
+
+** Matlab Init                                              :noexport:ignore:
+#+begin_src matlab :exports none :results silent :noweb yes
+  <<matlab-init>>
+#+end_src
+
+** Load data
+We load the data of the z axis of two geophones.
+#+begin_src matlab :results none
+  sr_off = load('mat/data_012.mat', 'data'); sr_off = sr_off.data;
+  sr_on = load('mat/data_013.mat', 'data'); sr_on  = sr_on.data;
+#+end_src
+
+** Time Domain
+We compare the signal when the Slip-Ring is OFF (figure [[fig:sr_geophone_time_off]]) and when it is ON (figure [[fig:sr_geophone_time_on]]).
+
+#+begin_src matlab :results none :exports none
+  figure;
+  hold on;
+  plot(sr_off(:, 3), sr_off(:, 1), 'DisplayName', 'Direct');
+  plot(sr_off(:, 3), sr_off(:, 2), 'DisplayName', 'Slip-Ring');
+  hold off;
+  legend('Location', 'northeast');
+  xlabel('Time [s]');
+  ylabel('Voltage [V]');
+#+end_src
+
+#+NAME: fig:sr_geophone_time_off
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/sr_geophone_time_off.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:sr_geophone_time_off
+#+CAPTION: Comparison of the time domain signals when the slip-ring is OFF
+#+RESULTS: fig:sr_geophone_time_off
+[[file:figs/sr_geophone_time_off.png]]
+
+#+begin_src matlab :results none :exports none
+  figure;
+  hold on;
+  plot(sr_on(:, 3),  sr_on(:, 1),  'DisplayName', 'Direct');
+  plot(sr_on(:, 3),  sr_on(:, 2),  'DisplayName', 'Slip-Ring');
+  hold off;
+  legend('Location', 'northeast');
+  xlabel('Time [s]');
+  ylabel('Voltage [V]');
+#+end_src
+
+#+NAME: fig:sr_geophone_time_on
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/sr_geophone_time_on.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:sr_geophone_time_on
+#+CAPTION: Comparison of the time domain signals when the slip-ring is ON
+#+RESULTS: fig:sr_geophone_time_on
+[[file:figs/sr_geophone_time_on.png]]
+
+** Frequency Domain
+We first compute some parameters that will be used for the PSD computation.
+#+begin_src matlab :results none
+  dt = sr_off(2, 3)-sr_off(1, 3);
+
+  Fs = 1/dt; % [Hz]
+
+  win = hanning(ceil(10*Fs));
+#+end_src
+
+Then we compute the Power Spectral Density using =pwelch= function.
+#+begin_src matlab :results none
+  % Direct measure
+  [pxdoff, ~] = pwelch(sr_off(:, 1), win, [], [], Fs);
+  [pxdon,  ~] = pwelch(sr_on(:, 1),  win, [], [], Fs);
+
+  % Slip-Ring measure
+  [pxsroff, f] = pwelch(sr_off(:, 2), win, [], [], Fs);
+  [pxsron,  ~] = pwelch(sr_on(:, 2),  win, [], [], Fs);
+#+end_src
+
+Finally, we compare the Amplitude Spectral Density of the signals (figure [[]]);
+
+#+begin_src matlab :results none
+  figure;
+  hold on;
+  plot(f, sqrt(pxdoff), 'DisplayName', 'Direct - OFF');
+  plot(f, sqrt(pxsroff), 'DisplayName', 'Slip-Ring - OFF');
+  plot(f, sqrt(pxdon),  'DisplayName', 'Direct - ON');
+  plot(f, sqrt(pxsron),  'DisplayName', 'Slip-Ring - ON');
+  hold off;
+  set(gca, 'xscale', 'log');
+  set(gca, 'yscale', 'log');
+  xlabel('Frequency [Hz]'); ylabel('ASD of the measured Voltage $\left[\frac{V}{\sqrt{Hz}}\right]$')
+  legend('Location', 'northeast');
+  xlim([0.1, 500]);
+#+end_src
+
+#+NAME: fig:sr_geophone_asd
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/sr_geophone_asd.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:sr_geophone_asd
+#+CAPTION: Comparison of the Amplitude Spectral Sensity
+#+RESULTS: fig:sr_geophone_asd
+[[file:figs/sr_geophone_asd.png]]
+
+#+begin_src matlab :results none :exports none
+  xlim([100, 500]);
+#+end_src
+
+#+NAME: fig:sr_geophone_asd_zoom
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/sr_geophone_asd_zoom.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:sr_geophone_asd_zoom
+#+CAPTION: Comparison of the Amplitude Spectral Sensity - Zoom
+#+RESULTS: fig:sr_geophone_asd_zoom
+[[file:figs/sr_geophone_asd_zoom.png]]
+
+** Conclusion
+#+begin_important
+- When the slip-ring is OFF, it does not add any noise to the measurement
+- When the slip-ring is ON, it adds significant noise to the signal
+#+end_important
+
+* Measure of the influence of the AC/DC option on the voltage amplifiers
+  :PROPERTIES:
+  :header-args:matlab+: :tangle meas_noise_ac_dc.m
+  :header-args:matlab+: :comments org :mkdirp yes
+  :END:
+
+#+begin_src bash :exports none :results none
+  zip data/meas_noise_ac_dc \
+      mat/data_012.mat \
+      mat/data_013.mat \
+      meas_noise_ac_dc.m
+#+end_src
+
+The data and matlab files are accessible [[file:data/meas_noise_ac_dc.zip][here]].
+
+** Measurement Description
+*Goal*:
+- Measure the influence of the high-pass filter option of the voltage amplifiers
+
+*Setup*:
+- One geophone is located on the marble.
+- It's signal goes to two voltage amplifiers with a gain of 60dB.
+- One voltage amplifier is on the AC option, the other is on the DC option.
+
+*Measurements*:
+First measurement (=mat/data_014.mat= file):
+| Column | Signal                     |
+|--------+----------------------------|
+|      1 | Amplifier 1 with AC option |
+|      2 | Amplifier 2 with DC option |
+|      3 | Time                       |
+
+Second measurement (=mat/data_015.mat= file):
+| Column | Signal                     |
+|--------+----------------------------|
+|      1 | Amplifier 1 with DC option |
+|      2 | Amplifier 2 with AC option |
+|      3 | Time                       |
+
+** Matlab Init                                              :noexport:ignore:
+#+begin_src matlab :exports none :results silent :noweb yes
+  <<matlab-init>>
+#+end_src
+
+** Load data
+We load the data of the z axis of two geophones.
+#+begin_src matlab :results none
+  meas14 = load('mat/data_014.mat', 'data'); meas14 = meas14.data;
+  meas15 = load('mat/data_015.mat', 'data'); meas15 = meas15.data;
+#+end_src
+
+** Time Domain
+The signals are shown on figure [[fig:ac_dc_option_time]].
+#+begin_src matlab :results none :exports none
+  figure;
+  hold on;
+  plot(meas14(:, 3), meas14(:, 1), 'DisplayName', 'Amp1 - AC');
+  plot(meas14(:, 3), meas14(:, 2), 'DisplayName', 'Amp2 - DC');
+  plot(meas15(:, 3), meas15(:, 1), 'DisplayName', 'Amp1 - DC');
+  plot(meas15(:, 3), meas15(:, 2), 'DisplayName', 'Amp2 - AC');
+  hold off;
+  legend('Location', 'northeast');
+  xlabel('Time [s]');
+  ylabel('Voltage [V]');
+  xlim([0, 100]);
+#+end_src
+
+#+NAME: fig:ac_dc_option_time
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/ac_dc_option_time.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:ac_dc_option_time
+#+CAPTION: Comparison of the signals going through the Voltage amplifiers
+#+RESULTS: fig:ac_dc_option_time
+[[file:figs/ac_dc_option_time.png]]
+
+** Frequency Domain
+We first compute some parameters that will be used for the PSD computation.
+#+begin_src matlab :results none
+  dt = meas14(2, 3)-meas14(1, 3);
+
+  Fs = 1/dt; % [Hz]
+
+  win = hanning(ceil(10*Fs));
+#+end_src
+
+Then we compute the Power Spectral Density using =pwelch= function.
+#+begin_src matlab :results none
+  [pxamp1ac, f] = pwelch(meas14(:, 1), win, [], [], Fs);
+  [pxamp2dc, ~] = pwelch(meas14(:, 2), win, [], [], Fs);
+
+  [pxamp1dc, ~] = pwelch(meas15(:, 1), win, [], [], Fs);
+  [pxamp2ac, ~] = pwelch(meas15(:, 2), win, [], [], Fs);
+#+end_src
+
+The ASD of the signals are compare on figure [[fig:ac_dc_option_asd]].
+#+begin_src matlab :results none :exports none
+  figure;
+  hold on;
+  plot(f, sqrt(pxamp1ac), 'DisplayName', 'Amp1 - AC');
+  plot(f, sqrt(pxamp2dc), 'DisplayName', 'Amp2 - DC');
+  plot(f, sqrt(pxamp1dc), 'DisplayName', 'Amp1 - DC');
+  plot(f, sqrt(pxamp2ac), 'DisplayName', 'Amp2 - AC');
+  hold off;
+  set(gca, 'xscale', 'log');
+  set(gca, 'yscale', 'log');
+  xlabel('Frequency [Hz]'); ylabel('ASD of the measured Voltage $\left[\frac{V}{\sqrt{Hz}}\right]$')
+  legend('Location', 'northeast');
+  xlim([0.1, 500]);
+#+end_src
+
+#+NAME: fig:ac_dc_option_asd
+#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
+#+begin_src matlab :var filepath="figs/ac_dc_option_asd.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
+  <<plt-matlab>>
+#+end_src
+
+#+NAME: fig:ac_dc_option_asd
+#+CAPTION: Amplitude Spectral Density of the measured signals
+#+RESULTS: fig:ac_dc_option_asd
+[[file:figs/ac_dc_option_asd.png]]
+
+** Conclusion
+#+begin_important
+
+#+end_important

slip-ring-test/readme.org

@@ -1,4 +1,5 @@
-* Measure of the noise of the Voltage Amplifier
+* DONE Measure of the noise of the Voltage Amplifier
+  CLOSED: [2019-05-06 lun. 09:00]
 - 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
@@ -11,7 +12,8 @@ meas5: Ampli ON 40dB
 meas6: Ampli ON 60dB
 meas7: Ampli ON 80dB
 
-* Measure of the noise induced by the Slip-Ring
+* DONE Measure of the noise induced by the Slip-Ring
+  CLOSED: [2019-05-06 lun. 09:28]
 Setup:
 - 0V is generated by the DAC of the Speedgoat
 - Using a T, one part goes to ADC
@@ -30,8 +32,8 @@ Measurements:
 - 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
+* DONE Measure of the noise induced by the slip ring when using a geophone
-
+  CLOSED: [2019-05-06 lun. 09:28]
 The geophone is located at the sample location
 The two Voltage amplifiers have the following settings:
 - AC
@@ -51,8 +53,8 @@ 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
+* DONE Measure of the influence of the AC/DC option on the voltage amplifiers
-
+  CLOSED: [2019-05-06 lun. 09:28]
 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.
@@ -62,4 +64,3 @@ Second column: DC
 
 - meas14: col-1 = amp1+AC. col-2 = amp2+DC.
 - meas15: col-1 = amp1+DC. col-2 = amp2+AC.
-