Roughness tester

Introduction

A roughness tester is an instrument used to measure the surface roughness of the materials, which is the measure of the fine irregularities of the surface, and it is used in the manufacturing, the quality control, the machining, and the many other industries for the assessment of the surface finish. The roughness tester measures the surface roughness by the use of a stylus that moves across the surface, and the vertical movements of the stylus are measured, and the roughness parameters, such as the Ra (the arithmetic average roughness), the Rz (the maximum height), and the other parameters, are calculated; the roughness tester consists of a measuring unit with the stylus and the drive, an electronic unit, and a display, and it provides the roughness parameters, with features such as the various cut-off lengths, the data logging, and the statistical analysis; the roughness tester is used for the measurement of the surface roughness of the machined parts, for the measurement of the surface finish of the manufactured products, for the quality control, for the process control, for the assessment of the wear and the friction, for the research, and for many other applications, and it is available as the portable and the bench-top models, with the various measurement ranges and the resolutions; the roughness tester is an essential instrument for the surface finish measurement. Roughness testers are used in the manufacturing, in the machining, in the automotive industry, in the laboratories, and for many other applications. With their surface roughness measurement, roughness testers are essential for the quality control.

Surface Roughness Tester LSRT-T2013

Surface Roughness Tester offers a vertical measuring range of 0 to 200 μm and a horizontal travel of up to 15 mm. It features a compact mechatronic design with an intuitive display. The...

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Surface Roughness Tester LSRT-T2012

Surface Roughness Tester features a diamond stylus radius of 10μm, ensuring accurate contact with the surface. It includes an Li-ion battery for continuous usage without frequent chargi...

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Surface Roughness Tester LSRT-T2011

Surface Roughness Tester offers an accuracy of ≤±10%, ensuring reliable and consistent measurements for various surface profiles. It incorporates multiple cutoff lengths for accurate a...

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Surface Roughness Tester LSRT-T2010

Surface Roughness Tester has a measuring range of 640 µm (-320 µm to +320 µm) for Z-axis and 17.5 mm for X-axis. This tester comprises of a main unit and an external drive unit, allow...

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Standards

ISO 4287:1997-Geometrical Product Specifications (GPS)-Surface texture: Profile method-Terms, definitions and surface texture parameters

ISO 4288:1996-GPS-Surface texture: Profile method-Rules and procedures for the assessment of surface texture

Complies with the above standards, but is not limited to them.

Features

1. Roughness tester (surface roughness gauge) for measuring surface texture, Ra/Rz/Rq parameters of machined parts.

2. Portable or benchtop profilometer using a stylus to trace and quantify surface roughness of engineering components.

3. Suitable for manufacturing, machining, automotive, aerospace, metalworking, quality control and research laboratories.

4. Includes probe/stylus, drive unit, controller/display, calibration standard, sample stage and operation manual.

5. Supports surface roughness measurement (Ra, Rz, Rq, Rmax, Rt) of metal, plastic, ceramic and composite parts.

FAQ

Q1: What testing scenarios is this tester mainly applied to?

A: The roughness tester (surface roughness tester, profilometer) is used in manufacturing, machining, automotive, aerospace, metalworking, medical device, energy, and quality control to measure the surface texture/roughness of machined and engineered components, quantifying parameters like Ra (arithmetic average roughness), Rz (average maximum height), Rq (root mean square), Rmax/Rt (maximum height), and Rsm (spacing) to verify that surface finish meets design specifications, which affects function (friction, wear, lubrication, fatigue, coating adhesion, sealing, appearance). It supports machining and metalworking (milled, turned, ground, lapped, polished parts - verify surface finish from machining operations (CNC milling, turning, grinding, honing, polishing); incoming inspection of raw materials (rod, bar, sheet), in-process QC (after each machining step), finished product verification), automotive (engine components (cylinder bores, crankshafts, camshafts, valve seats - surface finish affects friction, wear, lubrication, sealing), transmission (gears, shafts, bearings), body panels (paint adhesion, appearance), brake components (rotors, drums - surface roughness affects friction/braking), aerospace (turbine blades, engine components, structural parts - critical for fatigue, coating adhesion, aerodynamics; strict surface finish specs), medical devices (orthopedic implants (hip/knee stems - surface roughness affects bone ingrowth (osseointegration), surgical instruments, dental implants - precise surface specs), energy (oil/gas (drill pipe, valves, seals - surface finish affects sealing, corrosion, wear), power generation (turbine components, boiler tubes), bearings and seals (bearing surfaces (Ra affects friction, wear, lubricant retention), seal surfaces (too rough = leak, too smooth = poor lubrication), coating/plating (pre-plate surface preparation (roughness affects coating adhesion; too smooth = poor adhesion, too rough = coating defects), anodizing, painting), and research/QC (material science, tribology (friction/wear studies), surface engineering, process optimization, batch-to-batch consistency, calibration of machining processes).

Q2: What standards does the tester comply with?

A: The roughness tester follows relevant ISO, ASME, DIN, JIS and GB/T standards including ISO 4287 (surface texture: profile method - terms, definitions and surface texture parameters), ISO 4288 (rules and procedures for the assessment of surface texture), ISO 3274 (nominal characteristics of contact (stylus) instruments), ASME B46.1 (surface texture (surface roughness, waviness, and lay)), DIN 4762/4768 (surface roughness), JIS B0601 (surface roughness), and GB/T 3505/1031 (surface roughness parameters and measurement). The hardware complies with applicable precision standards (stylus tip radius 2 or 5 micrometers, measuring force <1 mN typically, vertical resolution nm to micrometer). Calibration uses certified roughness standard (calibration block with known Ra/Rz traceable to national standards) per ISO 4288/ASME B46.1. For regulated industries (aerospace, medical, automotive), follow ISO 9001/AS9100/ISO 13485 and maintain calibration records. For safety-critical components, specific industry standards (ASTM, SAE, ISO) may apply.

Q3: What is the warranty period for the whole tester and key components?

A: The whole roughness tester is covered by a 12-24 month warranty (precision instruments often 2 years). The stylus/probe (diamond tip), drive unit, controller/display, and housing are covered, while stylus (wear part - diamond tip wears over time, especially on rough/hard surfaces; can break if dropped/crashed - expensive replacement), calibration standard (wear/replaceable - standard block can wear/contaminate), and batteries (for portable models) are consumables/accessories. Damage from improper use, stylus crash/drop (diamond tip can break or wear - avoid hard stops, use proper traverse length), measuring surfaces too rough (beyond instrument range - can damage stylus), liquid/corrosive ingress, dropping (portable units), or unauthorized repair is excluded. Extended warranty and service contracts (calibration, stylus replacement) may be available. Electronics last 5-10 years; stylus needs periodic replacement (1-5 years depending on usage/surface hardness).

Q4: Is this device difficult to operate? Is professional training required?

A: Operation requires trained QC/metrology personnel (proper setup, parameter selection, result interpretation). We provide operation manuals, installation, and training. Proper instrument setup (portable: place on stable surface or use stand/tripod; ensure probe is perpendicular to surface (use guidance feet or stand); benchtop: mount probe on stand, place sample on stage, level), calibrate before use (using certified roughness standard (calibration block with known Ra, e.g., 0.1, 0.5, 1.0, 3.0 micrometers Ra); follow calibration procedure (traverse standard, verify reading matches certificate within tolerance; if off, recalibrate or service; calibrate at start of shift or after stylus change), sample preparation (ensure surface is clean (oil, chips, debris affect readings - clean with solvent/water, dry), flat and accessible (curved surfaces may require special setup or correction; very small features may be below measurement capability), orient traverse direction (perpendicular to lay (machining marks) for Ra measurement (standard); parallel to lay gives different (lower) values - always report direction), select measurement parameters (cutoff wavelength (lambda c / sampling length: 0.08, 0.25, 0.8, 2.5, 8 mm - choose based on expected roughness (rougher = larger cutoff; ISO 4288 specifies: Ra <0.1 -> 0.08, 0.1-0.5 -> 0.25, 0.5-10 -> 0.8, 10-80 -> 2.5 mm); evaluation length (typically 5 x cutoff = 5 sampling lengths), traverse length (evaluation length + approach/return), parameters (Ra (most common, arithmetic average), Rz (average of 5 maximum peak-valley heights), Rq (RMS), Rmax/Rt (maximum peak-valley), Rsm (peak spacing), Rsk (skewness), Rku (kurtosis) - select per drawing/spec), measurement execution (position stylus on surface (lower gently - do not crash), start traverse (stylus moves across surface at constant speed (0.5 mm/s typical), records vertical displacement), wait for completion (5-30 seconds depending on length), read result (display shows Ra/Rz/etc.; some show profile graph), repeat (3-5 measurements at different locations (surface roughness varies - report average and range; for critical parts, measure per spec (e.g., 3 locations)), post-measurement (raise stylus carefully, clean stylus (soft brush - do not touch diamond tip with fingers), clean sample, store probe in protected position), maintenance (regular cleaning (after each use - clean stylus with soft brush, clean calibration standard, wipe exterior), stylus inspection (check tip for wear/damage (under microscope if needed; worn tip gives lower Ra readings; replace if worn/damaged), calibration (every 6-12 months with certified standard (or more frequently if heavy use, after stylus change, if readings seem off); verify at multiple Ra values (e.g., 0.1, 1.0, 5.0 micrometers), battery check (portable - charge/replace), troubleshooting (readings inconsistent (surface not clean, traverse direction wrong, cutoff wrong, stylus worn, surface variation - clean, verify direction/cutoff, inspect stylus, measure multiple spots), readings too low (stylus worn (rounded tip), cutoff too small, traverse parallel to lay, surface too smooth for range - replace stylus, adjust cutoff, traverse perpendicular), readings too high (surface contaminated, cutoff too large, stylus damaged (chatter), vibration - clean, adjust cutoff, inspect stylus, stabilize), stylus not moving (drive issue, stylus crashed, battery low - service, check), calibration fails (standard worn/contaminated, stylus worn, instrument out of calibration - clean/replace standard, replace stylus, recalibrate/service), and safety (stylus hazard (diamond tip is sharp/hard - do not touch, avoid eye contact when lowering; crash can break stylus and damage sample), moving parts (keep fingers clear during traverse), electrical (proper grounding, rechargeable batteries - use approved charger), chemical (cleaning solvents - PPE), do not measure surfaces beyond instrument range (can damage stylus), handle portable unit carefully (dropping can break stylus and electronics) are important for accurate roughness measurement.

Q5: What is the typical lead-time for order delivery?

A: Standard models require 7-30 working days. In-stock units can ship within 3-7 working days. Custom configurations or large built-to-order systems may require additional time, and we confirm the exact schedule before order confirmation.

Q6: Is regular calibration required? What is the recommended calibration cycle?

A: Calibration recommended every 6-12 months (or per quality system) using certified roughness calibration standard (calibration block with known Ra/Rz traceable to national standards (NIST, PTB, NIM); verify at multiple Ra values spanning instrument range (e.g., 0.05, 0.5, 5.0 micrometers); accuracy typically +/- 5-10% of reading or +/- 0.01 micrometers). If stylus is replaced, instrument is dropped, or readings seem off, recalibrate immediately. Routine verification with calibration standard before each use or at start of shift (quick check). For ISO 17025/AS9100/ISO 13485 labs, follow applicable calibration schedules and maintain records (calibration certificates, standard ID, as-found/as-left data, stylus ID). Stylus wear is the main source of drift - regular calibration and stylus inspection ensure accuracy. Benchtop high-precision models may need more frequent calibration (every 3-6 months) and environmental control (temperature 20 +/- 1 degree C, vibration isolation).

Q7: Are supporting consumables universal?

A: Stylus/probe (replacement - specific to instrument model (different tip radius (2/5/10 micrometers), material (diamond, ruby), length; use manufacturer-approved stylus - third-party may not fit/calibrate correctly), calibration standard (roughness calibration block - certified, specific Ra values; somewhat universal if dimensions match, but use certified traceable standard), sample stands/clamps (for holding small/curved parts - specific or universal), batteries (portable - standard rechargeable), cleaning supplies (isopropyl alcohol, lens cloth, soft brush), and printer (for reports - standard or specific) are available from metrology supply companies, though stylus and calibration standards are often instrument-specific (use OEM or certified compatible to maintain accuracy and warranty). Long-term consumable cost includes stylus replacement (periodic, expensive ($300-$1000+)) and calibration standards (periodic if worn).

Q8: Can I customize parameters or supporting accessories?

A: Customization includes type (portable (battery-powered, handheld, for shop floor - convenient, moderate precision) or benchtop (higher precision, nm resolution, for lab/QC - more stable, longer traverse), measurement principle (stylus (contact - standard, high resolution, can damage soft surfaces) or optical (non-contact - laser, confocal, white light interferometry; for soft, delicate, or high-precision surfaces; no stylus wear; this entry is stylus-type), precision/range (vertical range (10-1000 micrometers), resolution (0.001-0.1 micrometers; higher = more expensive), traverse length (1-50 mm), parameters (Ra, Rz, Rq, Rt, Rsm, Rsk, Rku, Rc, Rp, Rv - selectable; 2D profile or 3D areal (Sa, Sz, etc.)), display/control (basic (LED, few parameters) or advanced (color display, profile graph, statistical analysis, memory, USB/Bluetooth/WiFi data export, software for PC analysis, 21 CFR Part 11 for pharma), probes (standard (2 micrometer tip, 90 degree cone), extra length (for deep grooves/recesses), small tip (for fine features), chisel (for specific lay), material (diamond (hard, durable), ruby (softer, for delicate surfaces)), accessories (calibration standards (multiple Ra values), sample stands, V-blocks (for cylindrical parts), magnetic base, printer, carrying case (portable), calibration certificate (ISO 17025), certifications (CE, ISO 9001, AS9100, ISO 13485), language and accessories. Additional styli, standards, and accessories can be ordered separately.

Q9: Does the purchase include on-site installation and commissioning service?

A: Standard delivery includes roughness tester, stylus, calibration standard, power cord/battery, and instruction manual. On-site installation, calibration, and operator training ARE typically included or strongly recommended for benchtop/high-precision models (precision metrology instruments requiring proper setup, calibration, and user training on parameter selection and measurement technique; installation by manufacturer or certified metrology technician is standard). For portable models: self-installation is feasible (charge, calibrate with standard, use) but initial training on proper technique (cutoff selection, traverse direction, stylus care) is recommended. Always verify with calibration standard before measuring parts.

Q10: What types of samples are compatible with this equipment?

A: The roughness tester measures surface roughness of various engineering materials and parts including metals (steel, stainless steel, aluminum, copper, brass, titanium, cast iron - machined, ground, polished, lapped, honed, shot-blasted surfaces), plastics (engineering plastics (ABS, PC, nylon, PEEK, PTFE - molded, machined; note: soft plastics may be scratched by stylus (use low force or optical)), ceramics (alumina, zirconia, silicon carbide - hard, brittle; polished/ground surfaces), composites (CFRP, GFRP, metal matrix composites - layered, fiber texture), glass (optical glass, hardened glass - polished surfaces; very smooth (nm range - may need high-precision optical)), coated/plated surfaces (anodized, chrome, nickel, paint, powder coating - coating roughness affects adhesion/appearance), and other solid materials with accessible flat or gently curved surfaces. NOT compatible with: Very soft materials (rubber, foam, gels - stylus penetrates/deforms; use optical), extremely rough surfaces (>80-100 micrometers Ra - beyond standard range; use other methods), very small/complex features (deep grooves, tiny holes - stylus cannot access; use microscope/optical), transparent/reflective surfaces (stylus works on most, but optical may be better for some), surfaces with loose debris/chips (must clean first), and liquid/wet surfaces (stylus methods require dry surface; water can affect reading). IMPORTANT: Surface roughness fundamentals: (1) What is surface roughness? The microscopic irregularities (peaks and valleys) on a machined/engineered surface, resulting from machining processes (tool marks, abrasive grit, plastic deformation). Quantified by parameters like Ra, Rz, Rq. Distinct from waviness (longer wavelength, from machine vibration/tool deflection) and form (overall shape). Cutoff wavelength separates roughness from waviness. (2) Key parameters: - Ra (arithmetic average roughness): Average absolute deviation of profile from mean line. Most common, widely specified. Units: micrometers (or microinches, 1 micrometer = 39.37 microinches). - Rz (average maximum height): Average of maximum peak-valley height over 5 sampling lengths. More sensitive to deep scratches/peaks than Ra. - Rq (RMS roughness): Root mean square deviation. Similar to Ra but mathematically RMS. - Rt/Rmax (total height): Maximum peak-to-valley over entire evaluation length. Worst-case. - Rsm (mean spacing): Average spacing between peaks. Related to texture/lay. - Rsk (skewness): Asymmetry of profile (positive = peaks dominate, negative = valleys dominate). Important for tribology (valleys retain lubricant). - Rku (kurtosis): Sharpness of peaks (spiky vs rounded). (3) Measurement setup: - Cutoff wavelength (lambda c): Filter that separates roughness from waviness. Choose based on expected Ra (ISO 4288): Ra 0.006-0.02 -> 0.08 mm; 0.02-0.1 -> 0.25; 0.1-0.5 -> 0.8; 0.5-10 -> 2.5; 10-80 -> 8 mm. Wrong cutoff gives wrong Ra. - Evaluation length: Typically 5 x cutoff (5 sampling lengths). - Traverse direction: Perpendicular to lay (machining marks) for standard Ra. Parallel to lay underestimates roughness. - Stylus: Diamond tip, 2 or 5 micrometer radius, 90 degree cone. Measuring force <1 mN (to avoid scratching). (4) Typical Ra values (micrometers): - Superfinished/lapped: 0.01-0.1 (optical, bearings, seals) - Ground: 0.1-0.8 (precision shafts, cylinders) - Milled/turned: 0.8-6.3 (general machined parts) - Sawed/cast: 6.3-25 (rough) - Forged/shot-blast: 25-100 (very rough) (5) Why roughness matters: - Friction/wear: Rougher surfaces = higher friction, faster wear (but some roughness helps retain lubricant). - Fatigue: Rough surfaces have stress concentrations at valley roots -> reduced fatigue life (critical for aerospace, automotive). - Sealing: Too rough = leaks; too smooth = no lubricant retention (seal surfaces have optimal Ra). - Coating adhesion: Proper roughness (anchor profile) improves coating/plating adhesion; too smooth = poor adhesion, too rough = coating defects. - Appearance: Smooth surfaces (low Ra) look glossy/refined; rough surfaces look matte/textured. - Corrosion: Rough surfaces have more area, can trap corrosive media (valleys) -> increased corrosion. - Electrical contact: Roughness affects contact resistance. (6) Stylus vs optical: - Stylus (contact): High resolution, robust, works on most materials, low cost, but can scratch soft surfaces, stylus wears, 2D only (line trace), limited aspect ratio (deep grooves). - Optical (non-contact): No surface damage, fast, 3D areal measurement, works on soft/delicate, but expensive, complex, affected by reflectivity/transparency, may have issues with steep slopes. (7) Common errors: - Wrong cutoff wavelength (biggest source of error). - Traverse parallel to lay (underestimates). - Not cleaning surface (debris/oil affects reading). - Worn stylus (underestimates Ra - rounded tip). - Measuring only one location (surface varies; measure multiple, report average). - Not calibrating (drift). - Exceeding range (damages stylus). - Not reporting parameters (Ra alone is incomplete; include Rz, cutoff, direction). - Confusing Ra and Rz (different values, different specs). (8) Standards: ISO 4287/4288 (international), ASME B46.1 (US), DIN 4768 (Germany), JIS B0601 (Japan), GB/T 3505 (China). Parameters and definitions may differ slightly between standards (e.g., Rz definition varies between ISO and old JIS) - always specify standard used.