Both the upside and the underside ofthe base are datum surfaces.The slider has two jaws on its left side andright side.Thejaw on the slider’s left is for the bottom measuring faceThejaw on the slider’s right is for the upside measuring face(When the base is on the inspection surface plate,the surface ofthe plate is regarded as the extension ofbottom measuring face.)
In case the inspection surface plate is unavailablethe upside ofthe base can be used as an inspection surface plate.
Measurement can still be done with the slider’s right jaw.
+Therange ofapplication can be widened with some attachments.