diff --git a/measurement_logging/src/measurement_logging/core.py b/measurement_logging/src/measurement_logging/core.py
new file mode 100644
index 0000000..83ee210
--- /dev/null
+++ b/measurement_logging/src/measurement_logging/core.py
@@ -0,0 +1,81 @@
+from __future__ import annotations
+
+import csv
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+import logging
+
+
+logging.basicConfig(level=logging.INFO, format='%(asctime)s [%(levelname)s] %(message)s')
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class Measurement:
+    """Dataclass zur strukturierten Repräsentation einer Messung."""
+    time: str
+    temperature: float
+    humidity: float
+    iso: int
+    exposure: float
+    rms_noise: float
+
+    @classmethod
+    def from_dict(cls, data: dict[str, Any]) -> 'Measurement':
+        required_fields = {"time", "temperature", "humidity", "iso", "exposure", "rms_noise"}
+        missing = required_fields - set(data.keys())
+        if missing:
+            raise ValueError(f"Fehlende Felder in Messdaten: {', '.join(sorted(missing))}")
+
+        try:
+            return cls(
+                time=str(data["time"]),
+                temperature=float(data["temperature"]),
+                humidity=float(data["humidity"]),
+                iso=int(data["iso"]),
+                exposure=float(data["exposure"]),
+                rms_noise=float(data["rms_noise"])
+            )
+        except (TypeError, ValueError) as e:
+            raise ValueError(f"Ungültige Datentypen in Messdaten: {e}") from e
+
+
+def log_measurement(time: str, temperature: float, humidity: float, iso: int, exposure: float, rms_noise: float, output_path: str | Path = "output/measurements.csv") -> None:
+    """Protokolliert eine Messung in einer CSV-Datei.
+
+    Schreibt bei Bedarf den Header, validiert Eingabewerte und fügt eine Datenzeile an.
+    """
+    measurement = Measurement.from_dict({
+        "time": time,
+        "temperature": temperature,
+        "humidity": humidity,
+        "iso": iso,
+        "exposure": exposure,
+        "rms_noise": rms_noise
+    })
+
+    output_file = Path(output_path)
+    output_file.parent.mkdir(parents=True, exist_ok=True)
+
+    header = ["time", "temperature", "humidity", "iso", "exposure", "rms_noise"]
+    write_header = not output_file.exists() or output_file.stat().st_size == 0
+
+    try:
+        with output_file.open(mode='a', newline='') as csvfile:
+            writer = csv.writer(csvfile)
+            if write_header:
+                writer.writerow(header)
+                logger.debug("CSV-Header geschrieben.")
+            writer.writerow([
+                measurement.time,
+                f"{measurement.temperature:.2f}",
+                f"{measurement.humidity:.2f}",
+                measurement.iso,
+                f"{measurement.exposure:.4f}",
+                f"{measurement.rms_noise:.4f}"
+            ])
+        logger.info(f"Messung erfolgreich protokolliert: {output_file}")
+    except OSError as e:
+        logger.error(f"Fehler beim Schreiben in CSV: {e}")
+        raise
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