Universal hardness tester Model 249 Smart XL

scratchtable-mountedfor coatings

Description
The LINEARTESTER 249 Smart XL is a tabletop scratch hardness tester designed to determine a coating or surface's resistance to damage by scratching. In addition to scratch/scribe testing it supports abrasion (single and double stroke), crockmeter, MEK and general wipe/solvent resistance tests.

Design
Tabletop device with capacitive LCD for settings and control. Electromotive drive provides uniform forward motion of the specimen slide. The test tool is lowered and lifted automatically for scratch/scribe tests. A wide range of test tips is available, some in tungsten carbide with a hard protective coating that reveals the underlying material when worn. An optional universal adapter set enables user-specific tool inserts.

Principle of the Test
The specimen panel is clamped on a movable slide. A reciprocating beam mounted on two pillars carries the test tool and a movable weight to set the scratching force (0.5–20 N standard; additional weights extend up to 40 N). The unit includes a 4-position height-adjustable load arm (standard ~10 mm; +20/+40/+60 mm available) — vertical adjustment requires sample clamping pieces. Operation is via the capacitive LCD. For scratch tests the tool lowers as the slide moves forward; lateral positioning permits multiple parallel scratches with different forces. For insulating coatings on conductive substrates, an electrical through-scratch detection is available. For abrasion, crockmeter, MEK or wipe tests the tool remains lowered and the slide moves in preset to-and-fro cycles; test speeds and stroke lengths are freely adjustable.

Scope of delivery

• Scratch Hardness Tester LINEARTESTER 249 Smart XL with electric motor drive; single-stroke test length 50–220 mm; double-stroke 35–260 mm (without test tool)
• Load weight 20 N
• Operating instructions

Standards
ISO 1518

Technical specifications

• Drive: Electric
• Test speed: Single stroke 10–100 mm/s; double stroke 10–400 mm/s (infinitely adjustable)
• Test length (single stroke): 50–220 mm
• Stroke length (double stroke): 35–260 mm (variable)
• Testing force: 0.5–40 N (additional load weights 1–40 N optionally available)
• Scratch profiles: Van Laar, Bosch, ISO, Clemen, etc.
• Specimen dimensions: up to 210 x 260 mm
• Portable / Stationary: Stationary (tabletop)
• Dimensions (L x W x H): approx. 680 x 380 x 325 mm
• Operation: capacitive LCD display; electromotive drive; automatic lowering/lifting for scratch tests

Accessories and options

• Wide range of test tips (including tungsten carbide tools with hard coating)
• MEK attachment, crockmeter attachment
• Universal adapter set for custom tool inserts
• Additional load weights; sample clamping pieces for vertical adjustment