Scratch hardness tester Model 249

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Overview
The LINEARTESTER 249 is a tabletop scratch hardness tester for industrial quality control. It is designed for scribe/scratch tests and can also perform to-and-fro abrasion tests, crockmeter tests, MEK and general solvent/wipe tests. The unit features an electromotive drive, automatic tool lowering/lifting and a broad range of interchangeable test tools. Optional adapters extend tool compatibility.

Principle of the test
The specimen plate is clamped to a mobile slide. A freely moving reciprocating beam mounted on two metal pillars carries the test tool and a movable weight. The scratching force (0.5–20 N) is set by shifting the weight on the beam; an additional load weight (1–40 N) is optional. A 4-position height-adjustable load arm (standard height ≈ 10 mm; +20/+40/+60 mm) is provided. An electric through-scratch detection is available for insulating coatings on conductive substrates.

Test modes and operation
Scratch/scribe tests are started by lowering the tool during the forward stroke; the guide plate (when used) lifts the tool on the return. For abrasion, crockmeter, MEK or wipe tests the tool remains lowered and the slide executes preset to-and-fro cycles. The guide plate is removed for these modes. The slide can be shifted laterally to produce adjacent scratches; an integrated ruler ensures uniform spacing. Three fixed test speeds plus one freely programmable speed are available.

Design and options
The LINEARTESTER 249 is a compact tabletop unit with an electromotive drive ensuring uniform slide motion. Optional features include a universal adapter set for custom tool inserts, additional load weights and variable stroke lengths (35, 50, 65, 80, 95 mm) in addition to the standard 60 mm stroke.

Technical data

• Drive: Electromotive
• Standard stroke length: 60 mm (optional: 35, 50, 65, 80, 95 mm)
• Scratch force range: 0.5–20 N
• Adjustable test force: 0.5–40 N (additional weight optional)
• Load arm height: 4-position (standard ≈ 10 mm; +20/+40/+60 mm)
• Max specimen size: up to 150 × 210 mm (DIN A5)
• Test speeds: fixed 25 / 35 / 200 mm/s; programmable 10–200 mm/s
• Dimensions (W×D×H): approx. 580 × 280 × 210 mm
• Net weight: approx. 13 kg
• Power supply: 100–240 VAC, 47–63 Hz
• Scratch geometries: Van Laar, Bosch, ISO, Clemen, etc.
• Stationary tabletop unit

Delivery / Accessories

• LINEARTESTER 249 with electromotive drive
• Hex key set
• Spirit level
• Power supply
• Operating manual

Standards

• ISO 1518