Perhaps you should try some spelling variations:
chemical measurements » physical measurements, medical measurements, mechanical measurements
physical measurement » physical measurements, clinical measurement, physiological measurement
optical measurement » optical measurements, physical measurements, inertial measurement

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((( physical measurement ) OR ( chemical measurements ))) OR ( optical measurement )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( physical measurement ) OR ( chemical measurements ))) or ( optical measurement ))".
• Adding a wildcard symbol may retrieve word variants: (((( physical measurement ) OR ( chemical measurements ))) or ( optical measurement ))*.