The Barcol Impressor is intended for handheld testing of hardness for aluminum and aluminum alloys, soft metals, plastics, fiberglass, rubber and leather. Harder materials cannot be tested with the Impressor. For information on other available models please contact our office.
To test a surface, place the indenter point and the leg of the impressor on the same plane of the surface. To insure reading accuracy, make certain that no indentations from previous use are within 1/16th of an inch of the present indenter point position. Readings should not be taken on both sides of the 1/32nd inch-thick test disks. Readings taken on top of old indentations will adversely affect the accuracy of the reading. An ample supply of appropriate test disks should be maintained for these reasons.
Press down firmly, but carefully, on the impressor handle. Observe the indicator, noting the peak reading. For softer materials there will be some falling-off of the reading from the peak value. This is normal and is due to the nature of the materials being tested.
As a general rule, you should increase the number of readings taken as the softness of the materials being tested increases.