diff --git a/src/backscattering_analyzer/analyzer.py b/src/backscattering_analyzer/analyzer.py
index 7805087..5a9b630 100644
--- a/src/backscattering_analyzer/analyzer.py
+++ b/src/backscattering_analyzer/analyzer.py
@@ -42,9 +42,9 @@ class Analyzer:
         self.settings.log("loading bench movement")
         try:
             data = loadtxt(file).T
-            self.bench_movement = Signal(
-                data[0], data[1], self.settings
-            )
+            self.bench_movement = (
+                Signal(data[0], data[1], self.settings) * 1e-6
+            )  # um
         except OSError:
             raise Exception("{file} does not exist".format(file=file))
 
@@ -56,8 +56,8 @@ class Analyzer:
         self.settings.log("loading mirror movement")
         try:
             data = loadtxt(file).T
-            self.mirror_movement = Signal(
-                data[0], data[1], self.settings
+            self.mirror_movement = (
+                Signal(data[0], data[1], self.settings) * 1e-6
             )
         except OSError:
             raise Exception("{file} does not exist".format(file=file))
@@ -146,10 +146,7 @@ class Analyzer:
         frequencies = zeros(results.shape[1])
 
         for index in range(len(self.coupling)):
-            phase = (
-                (index + 1) * 4 * pi / (self.settings.wavelength * 1e6)
-                # * 1e6 sinon la courbe n'est plus du tout la même
-            )
+            phase = (index + 1) * 4 * pi / self.settings.wavelength
 
             factor_n = (self.movement * phase).sin().psd().sqrt()
             coupling_n = self.coupling[0].abs()
@@ -163,22 +160,12 @@ class Analyzer:
             # no need to redefine it each time but simpler here
             frequencies = factor_n.x
 
-            """ # from theoric equation
             results[index] = (
                 sqrt(self.settings.scattering_factor[index])
                 * self.settings.power_in
                 / self.settings.power_out
                 * (coupling_n * factor_n + coupling_d * factor_d).y
             )
-            """
-            results[index] = ( # from matlab
-                sqrt(self.settings.scattering_factor[index])
-                * self.settings.wavelength
-                / (4 * pi)
-                * (coupling_n**2 * factor_n + coupling_d**2 * factor_d)
-                .sqrt()
-                .y
-            ) ** 2
 
         self.projection = Signal(
             frequencies,
diff --git a/src/backscattering_analyzer/settings.py b/src/backscattering_analyzer/settings.py
index e53c07b..bf6f5b7 100644
--- a/src/backscattering_analyzer/settings.py
+++ b/src/backscattering_analyzer/settings.py
@@ -1,4 +1,5 @@
 from pathlib import Path
+from tomllib import load
 from rich.console import Console
 from rich.theme import Theme
 
@@ -29,13 +30,12 @@ class Settings:
         self.verbose = False
         self.bench = "SDB1"
         self.date = "2023_03_24"
-        self.folder = Path("/home/demagny/data")
-        self.wavelength = 1.064e-6  # m
 
-        self.calib_bench = 1.15
-        self.calib_mirror = 1.15
-        self.scattering_factor = [1.3e-4, 1e-16]  # parameter to change
-        self.vibration_frequency = 0.2
+        with open("values.toml", "rb") as file:
+            values = load(file)
+
+        self.folder = Path(values["general"]["data_folder"])
+        self.wavelength = values["interferometer"]["wavelength"]
 
         index = 0
         while index < len(options):
@@ -125,22 +125,27 @@ class Settings:
                 pass
             index += 1
 
-        if self.date == "2023_03_24":
-            self.modelisation = "scatterCouplingO4.mat"
-            self.power_in = 23  # W
-            self.power_out = 8e-3  # W
-        elif self.date == "2023_12_21":
-            self.modelisation = "scatterCouplingMisalignSR.mat"
-            self.power_in = 12.1  # W
-            self.power_out = 8e-3  # W
-        elif self.date == "2024_01_21":
-            self.modelisation = "scatterCouplingMisalignSR.mat"
-            self.power_in = 12.1  # W
-            self.power_out = 8e-3  # W
-        else:
-            self.modelisation = "scatterCouplingO4.mat"
-            self.power_in = 23  # W
-            self.power_out = 8e-3  # W
+        if not self.bench in values["benches"].keys():
+            raise ValueError("unknow bench {}".format(self.bench))
+
+        self.calib_mirror = values["benches"][self.bench]["calib"][
+            "mirror"
+        ]
+        self.calib_bench = values["benches"][self.bench]["calib"][
+            "bench"
+        ]
+        self.scattering_factor = values["benches"][self.bench][
+            "scatter_factor"
+        ]
+
+        if not self.date in values["dates"].keys():
+            raise ValueError("unknow date {}".format(self.date))
+
+        self.power_in = values["dates"][self.date]["power_in"]
+        self.power_out = values["dates"][self.date]["power_out"]
+        self.modelisation = values["dates"][self.date]["modelisation"]
+
+        self.vibration_frequency = 0.2
 
     def bench_file(self) -> Path:
         return self.folder / (
diff --git a/src/backscattering_analyzer/signal.py b/src/backscattering_analyzer/signal.py
index 710043d..8efdfc1 100644
--- a/src/backscattering_analyzer/signal.py
+++ b/src/backscattering_analyzer/signal.py
@@ -124,7 +124,7 @@ class Signal:
             self.y,
         )
 
-    def __sub__(self, other: float | Signal) -> Signal:
+    def __sub__(self, other: float | NDArray | Signal) -> Signal:
         """
         Substract float or a signal to another
         """
@@ -146,7 +146,7 @@ class Signal:
                 self.settings,
             )
 
-    def __add__(self, other: float | Signal) -> Signal:
+    def __add__(self, other: float | NDArray | Signal) -> Signal:
         """
         Add a float or a signal to another
         """
@@ -168,7 +168,7 @@ class Signal:
                 self.settings,
             )
 
-    def __mul__(self, other: float | Signal) -> Signal:
+    def __mul__(self, other: float | NDArray | Signal) -> Signal:
         """
         Multiply a signal by a value or another signal
         """
@@ -190,6 +190,28 @@ class Signal:
                 self.settings,
             )
 
+    def __truediv__(self, other) -> Signal:
+        """
+        Divide a signal by a value
+        """
+        if isinstance(other, Signal):
+            if len(other) != len(self):
+                signal_1, signal_2 = interpolate((self, other))
+            else:
+                signal_1, signal_2 = self, other
+
+            return Signal(
+                signal_1.frequencies,
+                signal_1.y / signal_2.y,
+                self.settings,
+            )
+        else:
+            return Signal(
+                self.x,
+                self.y / other,
+                self.settings,
+            )
+
     def __array__(self) -> NDArray:
         """
         Convert to a numpy array