2 files changed, 8 insertions, 1 deletions
diff --git a/lab_control/frequency_response.py b/lab_control/frequency_response.py
index af78840..6508d80 100644
--- a/lab_control/frequency_response.py
+++ b/lab_control/frequency_response.py
@@ -26,6 +26,9 @@ class FrequencyResponseMeasurement(Measurement):
         self.measurementDone = True
 
     def dumpToCSV(self, path: Path) -> None:
+        if self.data is None:
+            return
+
         with open(path, "w") as f:
             f.write("Frequency (Hz),Amplitude (V)")
 
diff --git a/lab_control/test/frequency_response_test.py b/lab_control/test/frequency_response_test.py
index ad47d53..2997413 100644
--- a/lab_control/test/frequency_response_test.py
+++ b/lab_control/test/frequency_response_test.py
@@ -58,11 +58,15 @@ def test_dumpToCSV(uut, mockLab, tmp_path):
     uut.minFrequency = 10.0
     uut.maxFrequency = 30.0
     uut.steps = 5
+    csv = tmp_path / "data.csv"
+
+    assert not csv.exists()
+    uut.dumpToCSV(csv)
+    assert not csv.exists()
 
     expectedData = prepareRampResponse(uut, mockLab)
     uut.measure(mockLab, mockLab)
 
-    csv = tmp_path / "data.csv"
     uut.dumpToCSV(csv)
     savedData = csv.read_text().split("\n")