Barcol impressor hardness tester
Portable The Impressor is a convenient tool for testing the hardness of aluminum, aluminum alloys, copper, brass and other materials including plastics and fiberglass. The instrument is designed for use on fabricated parts and assemblies as well as on raw stock.
Easy to Use No experience required; can be used in any position and in any space that will allow for the operator's hand. The hardness reading is instantly indicated on the dial, which is divided into one hundred graduations. No waiting, pre-loading or separate measurements.
Lightweight The Impressor weighs only 1 lb. 2 oz. The entire Impressor package comes complete with carrying case, adjusting wrench and two spare indenter points. The Impressor + case = 2 lb. 8oz. Shipping weights = 4 pounds, box = 12 x 11 x 6 inches, dimensional weight 5 pounds. (1.8 kilograms, box = 21 x 28 x 16 cm, dimension weight 2.5 Kilograms)
Four Models
GYZJ 934-1 for soft metals such as aluminum and its alloys, brass, copper, and some of the harder plastics and fiberglass. Approximate range 25 to 150 Brinell (10 mm ball 500 kg load). This unit meets American Society for Testing and Materials (ASTM) Standard D­2583.
GYZJ 934-1-0-1 a variation of the 934-1 that has a "flat bottom" shaped support leg. This is used to sit on top of the crest of the round rung of a ladder such as a fire department ladder. Approved by the NFPA, National Fire Protection Agency.

GYZJ 935 for the softer plastics and very soft metals.
GYZJ 936
for extremely soft materials such as lead, linoleum and leather.
The Impressor is best suited for testing homogeneous materials. Materials of granular, fibrous or coarse structure will produce a wide variation in hardness readings because of the small diameter of the indenter point.

For accurate readings, material should be at least 1 /32"thick and large enough for a minimum distance of 1/8" in any direction from the indenter point to the edge of the specimen. The testing area should be smooth and free from mechanical damage.

Simply exert alight pressure against the instrument to drive the spring-loaded indenter point into the material. The indenter point must be perpendicular to the surface being tested. On very soft metals, the highest reading should be used since cold flow permits the spring loaded indenter point to continue penetration.

Note: Physical characteristics of very soft materials are such that uniform correlation between different hardness measuring systems cannot be established. We recommend that Impressor hardness limits for each material be established by test.