df.loc[df['Measurement']>6,'drop'] = 'Y'

l = df.index[df['drop'] == 'Y'].tolist()
l_drop = []
for i in l:
    l_drop.append(i-1)
    l_drop.append(i+1)
    l_drop.append(i+2)

df.drop(df.index[l_drop],inplace=True)