diff --git a/pyAvantes/raw8.py b/pyAvantes/raw8.py
index f8a6a78..a227553 100644
--- a/pyAvantes/raw8.py
+++ b/pyAvantes/raw8.py
@@ -58,7 +58,7 @@ def __init__(self, filename: str):
                     dat = dat[0]
                 self.header[k[0]] = dat
             dataLength =  self.header['stopPixel']-self.header['startPixel']+1
-            self.dataLenth = dataLength
+            self.dataLength = dataLength
             self.data = {
                 'wl': struct.unpack(f"<{dataLength}f",f.read(4*dataLength)),
                 'scope': struct.unpack(f"<{dataLength}f",f.read(4*dataLength)),