diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index bad6356895c5b01aacc33fa42fa38d29f7e172d9..eec9bbcbf96519653854c928eaeb67ea26c829c8 100644
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -113,6 +113,7 @@ class Instrument:
         else:
             self.t0 = float(t0)
         self.fs = 1 / self.dt
+        self.duration = self.dt * self.size
         logger.info("Computing measurement time vector (size=%s, dt=%s)", self.size, self.dt)
         self.t = self.t0 + numpy.arange(self.size, dtype=numpy.float64) * self.dt