Krebs stormer viscometer

Introduction

A Krebs Stormer viscometer is a rotational viscometer used to measure the viscosity of the paints, the coatings, the inks, and the other fluids, and it is used in the paint, the coating, the ink, and the many other industries for the quality control and the process control. The Krebs Stormer viscometer measures the viscosity by the measurement of the torque required to rotate a paddle or a spindle in the sample at a specified speed, and the viscosity is expressed in Krebs units (KU), which is a unit used for the paints and the coatings, and it may also provide the viscosity in the other units, such as the poise and the centipoise, using the conversion; the Krebs Stormer viscometer consists of a rotating spindle or a paddle, a drive system, a torque measurement system, and a display, and it provides a rapid and a simple measurement, with features such as the digital display and the temperature measurement; the Krebs Stormer viscometer is used for the measurement of the viscosity of the paints and the coatings, for the measurement of the viscosity of the inks and the pastes, for the quality control in the production, for the adjustment of the viscosity, for the research and the development, and for many other applications, and it is available as the manual and the digital models; the Krebs Stormer viscometer is an essential instrument for the viscosity measurement of the paints and the coatings. Krebs Stormer viscometers are used in the paint and the coating industry, in the ink industry, in the adhesive industry, in the laboratories, and for many other applications. With their viscosity measurement, Krebs Stormer viscometers are essential for the quality control.

Krebs Stormer ViscometerLKSV-T2011

Krebs Stormer Viscometer offers repeatability of ± 0.5%, providing accurate and precise viscosity readings. It features low shear viscosity testing for measuring fluids with low viscosi...

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Krebs Stormer Viscometer LKSV-T2012

Krebs Stromer Viscometer is designed with a 500 ml sample container, allowing accurate testing of larger fluid volumes in a single run. It features an display of viscosity values and tes...

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Krebs Stormer Viscometer LKSV-T2010

Krebs Stormer Viscometer offers an accuracy of ±1.0%, ensuring precise viscosity measurements for consistent product quality. It features an automated motor drive to ensure uniform padd...

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Standards

ISO 3219:1993-Plastics-Determination of viscosity using a rotational viscometer with defined shear rate

ASTM D2196-20-Standard Test Methods for Rheological Properties of Non-Newtonian Materials by Rotational Viscometer

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

Features

1. Krebs Stormer viscometer for measuring viscosity of paints, coatings, inks and adhesives in Krebs Units (KU).

2. Rotational viscometer using a paddle-shaped spindle rotating at 200 RPM, measuring torque to report KU viscosity.

3. Suitable for paint, coating, ink, adhesive, chemical, cosmetic and quality control laboratories.

4. Includes viscometer body, Krebs spindle, stand, sample cup, display, power cord and operation manual.

5. Supports viscosity measurement in KU (Krebs Units), grams (g), and centipoise (cP) for paints and coatings per ASTM D562.

FAQ

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

A: The Krebs Stormer viscometer is used in paint, coating, ink, adhesive, chemical, cosmetic, and quality control laboratories to measure the viscosity of paints, coatings, inks, and similar non-Newtonian fluids using the Krebs method (paddle spindle at 200 RPM), reporting viscosity in Krebs Units (KU) - the standard unit for paint and coating viscosity in the industry. It supports paint and coatings manufacturing (QC of latex paints, enamels, epoxies, polyurethanes, acrylics, primers, varnishes - KU viscosity is a key quality parameter (typical: 80-120 KU for brush/roll paints, 70-90 for spray); batch consistency, formulation adjustment (thinning with water/solvent to target KU), incoming raw material inspection), ink (printing inks (offset, flexo, gravure, screen) - viscosity affects print quality, but note: some inks use other viscometers (e.g., Zahn cup); Krebs is mainly for paints), adhesives and sealants (PVA glues, caulks, acrylic adhesives - viscosity affects application, dispensing, bond strength), chemicals (polymer emulsions, latex, resin solutions, pigment dispersions - process and QC), cosmetics (creams, lotions, gels, foundations - texture and application, though cosmetics often use other viscometers), and research/QC (formulation development, process optimization, batch-to-batch consistency, comparison to standards). The Krebs method: A paddle-shaped spindle (specific geometry per ASTM D562) is immersed in the sample and rotated at a fixed 200 RPM. The torque required to maintain 200 RPM is measured and converted to Krebs Units (KU). KU is an empirical unit specific to this method (not directly comparable to cP without conversion, though many meters display g and cP equivalents). KU range: typically 40-140 KU (paints 70-120 KU). The method is fast (seconds), simple, and the standard for paint/coating QC per ASTM D562 and ISO 1522? (note: ISO uses different methods; KU is primarily US/ASTM standard).

Q2: What standards does the viscometer comply with?

A: The Krebs Stormer viscometer follows relevant ASTM, ISO and GB/T standards including ASTM D562 (standard test method for consistency of paints using Stormer-type viscometer - the primary standard for KU viscosity), ASTM D2196 (standard test methods for rheological properties of non-Newtonian materials by rotational viscometer - general rotational), ISO 1522 (paints and varnishes - determination of consistency (but ISO uses cone-and-plate or other, not KU specifically)), and GB/T standards for paint viscosity. The hardware complies with applicable accuracy standards (KU accuracy +/- 1-2 KU typical, speed 200 RPM +/- 1%), and EMC (IEC 61326). Calibration uses certified viscosity standard oils (traceable to NIST/PTB/NIM) or a certified Krebs calibration standard (some manufacturers provide KU calibration weights/standards). For paint/coating QC, follow ASTM D562 strictly (specific spindle, 200 RPM, sample cup size, temperature 25 degrees C (or 23 degrees C per some specs)). For regulated industries (automotive, aerospace coatings), follow applicable material specifications and quality systems (ISO 9001, IATF 16949). The Krebs spindle geometry and speed are defined by ASTM D562 - using the correct spindle is essential (not interchangeable with standard Brookfield spindles).

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

A: The whole Krebs Stormer viscometer is covered by a 12-24 month warranty (lab/QC instruments often 1-2 years). The motor, drive system, torque sensor, controller/display, and stand are covered, while Krebs spindle/paddle (wear part - can bend, corrode, wear; handle carefully; replacement available), sample cup (consumable - glass or metal, can break), and fuses are consumables/accessories. Damage from improper use, spindle bending (dropping, forcing into viscous sample, improper storage - use guard, handle carefully), liquid ingress into motor housing (spills, overfilling sample cup - clean promptly), using wrong spindle (non-Krebs spindle gives non-standard readings), overloading (exceeding viscosity range - can stall/damage motor), dropping, or unauthorized repair is excluded. Extended warranty and service contracts (calibration, spindle replacement) may be available. Motor/torque sensor last 5-10 years; spindle needs periodic replacement if bent/corroded (1-5 years depending on use/cleaning).

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

A: Operation is simple for basic KU measurement. No professional training required for routine use, but proper technique (sample prep, temperature control, spindle handling) is important for accuracy (paint viscosity is temperature-dependent and non-Newtonian). We provide operation manuals. Proper setup (place viscometer on stable, level bench (use built-in level; vibration affects readings), mount on stand with proper height adjustment, ensure Krebs spindle is securely attached (finger-tight, do not over-tighten), connect power, turn on, allow warm-up (15-30 min for motor/torque stabilization), verify speed (200 RPM - some meters display; verify with tachometer if needed), sample preparation (ensure sample is homogeneous (stir thoroughly but avoid entraining air - bubbles cause low/inconsistent readings; for paints, mix per ASTM D562 (stir 2-3 min, let stand to release bubbles)), pour into standard sample cup (specific size per ASTM D562 - typically 1/2 pint or specified container; fill to mark), temperature control (CRITICAL: paint viscosity is highly temperature-dependent (~2-5% per degree C); control at 25 +/- 0.5 degrees C (or 23 degrees C per spec) using water bath or temperature-controlled room; allow sample to equilibrate (30-60 min); always report temperature), measurement execution (lower spindle into sample until immersed to immersion mark (Krebs spindle has specific immersion depth - ensure paddle is fully submerged, not touching cup bottom/walls), ensure spindle is centered in cup, start rotation (200 RPM), allow reading to stabilize (30-60 sec; for thixotropic paints, reading time matters - specify read time per ASTM), read KU value (display shows KU; some also show grams (g) and cP equivalents), repeat (2-3 measurements for precision; for thixotropic materials, use fresh sample or standardize rest time (shear history affects viscosity)), post-measurement (stop rotation, raise spindle, remove sample, clean spindle immediately (wipe with appropriate solvent - water for water-based, alcohol/mineral spirits for solvent-based; do not use abrasive materials; remove spindle carefully (do not bend), clean sample cup, store spindle in rack/case (do not leave attached long-term), maintenance (daily: clean spindle and cup after use, wipe exterior, check level; weekly: inspect spindle for bending/corrosion, clean stand, verify speed (tachometer); monthly: full calibration with certified standard oil or KU calibration standard, lubricate (per manufacturer), troubleshooting (readings inconsistent (temperature fluctuation, air bubbles in sample, sample not homogeneous, thixotropy (reading time not standardized), spindle touching cup, vibration - control temp, degas, mix, standardize time, center spindle, stabilize), readings too high (spindle not fully immersed, sample temperature too low, wrong spindle (not Krebs), calibration off - immerse to mark, warm sample, use correct spindle, recalibrate), readings too low (air bubbles, spindle bent, sample temp too high, speed not 200 RPM - degas, replace spindle, cool sample, verify speed), motor not running/stalling (sample too viscous (over range), power issue, motor failure, spindle jammed - use appropriate range, check power, service), calibration fails (standard oil expired, spindle damaged, torque sensor drift - use fresh standard, replace spindle, service), and safety (SAMPLE HAZARD (paints, coatings, inks, solvents may contain VOCs, flammable solvents, toxic components (lead in old paints, pigments) - use fume hood for solvent-based samples, wear PPE (gloves, lab coat, eye protection, respirator if high VOC), ensure ventilation; dispose waste per regulations (hazardous waste for solvent-based paints)), MOVING SPINDLE (keep fingers/hair/clothing away when rotating; do not touch spinning paddle; pinch/injury hazard), CHEMICAL (cleaning solvents (mineral spirits, alcohol, xylene) - flammable, use fume hood, no open flame, PPE; water-based cleaners for latex), ELECTRICAL (proper grounding, do not use with wet hands, do not spill liquid into motor housing), do not exceed viscosity range (can stall/damage motor), handle Krebs spindle carefully (it is a precision paddle - bending changes geometry = inaccurate readings; do not use as stirrer), for solvent-based paints: ensure fire safety (no sparks, no open flame, explosion-proof area if required), do not leave spindle in sample (can corrode/bond - clean promptly)) are important for accurate KU viscosity 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 viscosity standard oils (NIST-traceable, e.g., 1000, 5000, 10000 cP) or a manufacturer-provided KU calibration standard/weight; verify KU reading at low/mid/high range covering expected paint viscosities (e.g., 50, 90, 120 KU); speed verification (200 RPM) with tachometer. If viscometer is moved, spindle replaced, motor serviced, or readings seem off, recalibrate immediately. Routine verification: check with a standard oil or reference paint before each batch or at start of shift (quick check). For ISO 17025/automotive/aerospace QC labs, follow applicable calibration schedules and maintain records (calibration certificates, standard lot/viscosity, as-found/as-left data, spindle ID, speed verification). Paint KU viscosity is critical for product quality (application properties) - regular calibration is essential. Krebs spindle geometry is key - if bent or damaged, replace and recalibrate. Note: some traditional Stormer viscometers use a weight-and-pulley system (load weights to reach 200 RPM) - these are calibrated with weights; modern digital versions use torque sensor and motor speed control.

Q7: Are supporting consumables universal?

A: Krebs spindle/paddle (replacement - specific to viscometer brand and ASTM D562 geometry; use OEM or certified compatible with correct dimensions (paddle size, shaft length) to maintain KU accuracy), sample cups (standard 1/2 pint or specified - glass or metal, somewhat universal if dimensions match ASTM D562), viscosity standard oils (certified, universal from lab supply (Cannon, Paragon, Brookfield) - use NIST-traceable), temperature probe (if included - specific or universal), cleaning supplies (solvents, wipes), and stands are available from paint/lab supply companies, though the Krebs spindle is specific (use OEM or certified compatible to maintain ASTM D562 compliance and accuracy). Long-term consumable cost includes spindle replacement (periodic, $50-$200) and calibration standards (regular purchase).

Q8: Can I customize parameters or supporting accessories?

A: Customization includes type (traditional weight-and-pulley Stormer (load weights to achieve 200 RPM, measure weight -> KU; older, manual) or digital motorized (motor maintains 200 RPM, torque sensor -> KU display; modern, easier, more consistent)), display (analog (weight/grams) or digital (LED/LCD, direct KU reading, also grams and cP equivalents, data logging)), speed (fixed 200 RPM per ASTM D562 - standard; some variable speed for research), temperature (integrated temperature probe or external water bath for sample temp control), data/connectivity (basic (KU display only) or advanced (data logging, USB/RS232 export, PC software, statistics, GLP/GMP compliance)), construction (benchtop (lab/QC) or portable (field, battery - less common for Krebs), accessories (extra Krebs spindles, sample cups (multiple), calibration standard oil, temperature probe/water bath, spare fuses, carrying case, calibration certificate (ISO 17025), certifications (CE, ISO 9001, ASTM D562 compliance), language and accessories. Additional spindles, cups, and accessories can be ordered separately.

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

A: Standard delivery includes Krebs Stormer viscometer, Krebs spindle, stand, sample cup, power cord, and instruction manual. On-site installation is not required for standard benchtop models (assemble stand, attach spindle, calibrate, use). On-site training is not included for standard orders but can be arranged at additional cost (for paint QC teams on ASTM D562 procedure, temperature control, sample prep, calibration, and GMP documentation). Remote guidance provided. Always calibrate with certified standard before measuring production samples.

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

A: The Krebs Stormer viscometer measures viscosity of paints, coatings, and related fluids including architectural paints (latex, acrylic, enamel, oil-based - interior/exterior, primers, topcoats), industrial coatings (epoxies, polyurethanes, alkyds, powder coatings (as liquid slurry), automotive coatings, marine coatings), inks (some printing inks, though many use Zahn/Ford cups or other viscometers; Krebs for paste/viscous inks), adhesives (PVA, acrylic, latex, caulks, sealants - paste to liquid), polymers/resins (emulsions, latex, resin solutions, pigment dispersions, pastes), cosmetics (creams, lotions, gels, pastes - if KU range appropriate), and other non-Newtonian fluids (shear-thinning, thixotropic) in the KU range (~40-140 KU, roughly 100-100000 cP). NOT compatible with: Very low-viscosity fluids (<40 KU, e.g., solvents, water, thin oils - below range; use capillary or other rotational viscometer), very high-viscosity pastes (>140 KU, e.g., heavy greases, dough, sealant pastes - may stall motor; use higher-torque viscometer or texture analyzer), samples with large particles/aggregates that jam paddle (filter or use appropriate method), non-liquid solids (viscosity is for fluids), samples that attack spindle material (verify compatibility of spindle (stainless steel usually) with sample; strong acids may corrode - use coated spindle or other method), and samples requiring precise rheological characterization (flow curves, yield stress - Krebs is a single-point QC test at 200 RPM, not a full rheometer; use cone/plate or rotational rheometer for detailed rheology). For thixotropic paints: KU reading depends on shear history and reading time - follow ASTM D562 strictly (mix, wait, measure at specified time) for reproducible results. IMPORTANT: Krebs Stormer viscometer fundamentals: (1) What it measures: Viscosity (consistency) of paints/coatings in Krebs Units (KU) using a paddle-shaped spindle rotating at 200 RPM. KU is an empirical unit defined by ASTM D562 - specific to this method and spindle. Not directly comparable to cP (centipoise) without conversion (though many meters provide approximate cP/grams). (2) How it works: - Traditional Stormer: A paddle spindle is immersed in sample. Weights are added to a pulley system until the spindle rotates at exactly 200 RPM. The weight required (in grams) is converted to KU (KU = function of weight). Manual, but accurate. - Digital Stormer: A motor rotates the paddle at controlled 200 RPM. A torque sensor measures the torque required. Torque is converted to KU (and grams, cP) electronically. Faster, easier, more consistent. (3) Krebs Units (KU): - Empirical scale for paint viscosity. - Typical ranges: - 40-60 KU: very thin (sprayable, stains) - 60-80 KU: thin (spray paints, glazes) - 80-100 KU: medium (brush/roll latex paints - most common target) - 100-120 KU: thick (heavy-bodied paints, caulks, texture coatings) - 120-140 KU: very thick (pastes, sealants) - KU is NOT the same as cP. Approximate: 100 KU ~ 1000-3000 cP (varies by fluid type). Always report KU, not converted cP, for paint QC. (4) ASTM D562 requirements: - Spindle: Specific paddle geometry (defined in standard). - Speed: 200 RPM (exact). - Sample container: Specified size (1/2 pint can or equivalent). - Immersion depth: Specific (spindle immersion mark). - Temperature: 25 +/- 0.5 degrees C (or 23 degrees C per some specs; always report). - Procedure: Mix sample, eliminate bubbles, immerse spindle, rotate, read after stabilization. (5) Why KU for paints? - Paints are non-Newtonian (shear-thinning, thixotropic). A single-point test at fixed shear (200 RPM paddle) gives a practical QC number correlated with application properties (brushing, rolling, spraying, sagging, leveling). - KU is the industry standard in North America (ASTM); paint formulators and QC use it daily. - Fast, simple, robust for production QC. (6) Key factors affecting KU readings: - Temperature (biggest): Paint viscosity changes ~2-5% per degree C. MUST control and report temperature. - Shear history (thixotropy): Paints thin under shear and recover over time. Reading depends on how long after mixing/shearing. Follow standardized procedure (mix, wait X minutes, measure). - Air bubbles: Entrained air lowers viscosity (false low). Degas/let stand. - Spindle condition: Bent or corroded paddle changes geometry = wrong readings. - Immersion depth: Must be at mark (too shallow = low, too deep = high). - Sample homogeneity: Pigment settling (stir before testing). (7) Common errors: - Wrong temperature (biggest - always control at 25 C). - Not following shear history protocol (read immediately after mixing vs after waiting = different results). - Air bubbles in sample (low readings). - Wrong spindle (not ASTM D562 Krebs paddle). - Spindle touching cup bottom/walls (high readings). - Reading too soon (before stabilization - thixotropic paints need time). - Using KU interchangeably with cP (they are not equivalent - report KU for paint). - Not cleaning spindle promptly (dried paint is hard to remove, can damage paddle). - Overloading (sample too viscous - stalls motor). (8) Krebs vs other viscometers: - Krebs Stormer: Paint/coating QC, KU units, fast, simple, single shear rate. - Brookfield rotational: General fluids, cP, multiple spindles/speeds, flow curves. - Cone/plate rheometer: Precise rheology, small samples, yield stress, full flow curves. - Zahn/Ford cup: Simple efflux cup (seconds), for thin paints/inks (field use, less precise). - For paint QC in North America: Krebs (KU) is standard. For Europe/ISO: ISO 1522 (cone-and-plate) or other methods. (9) Calibration: - Use certified viscosity standard oils (NIST-traceable) at multiple points. - Verify 200 RPM speed with tachometer. - Some manufacturers provide KU-specific calibration standards or weights. - Calibrate every 6-12 months, or after spindle replacement/motor service.