Poulten Selfe & Lee

What Poulten Selfe & Lee does

Poulten Selfe & Lee Limited (trading as PSL Rheotek) is a UK-headquartered specialist manufacturer of capillary viscometry instruments, founded in 1850 and based in Burnham-on-Crouch, Essex, with a US service office in Granger, Indiana. The company designs, manufactures, and calibrates precision glass capillary viscometers (Ubbelohde, Cannon-Fenske, U-Tube, Zeitfuchs Cross-Arm, Suspended-Level), constant-temperature viscometer baths with ±0.01°C stability, certified viscosity reference standards, and the automated RPV-1 and RPV-3 polymer viscometer systems for intrinsic viscosity, K-value, and limiting viscosity number testing. PSL maintains a primary viscosity scale traceable to double distilled water at 20°C under a UKAS ISO 17025 accredited calibration laboratory (Laboratory No. 0247), enabling all certificates to be issued directly traceable to this primary reference — a capability few laboratories worldwide possess. Complementary product lines include the iSP-1, iSP-2, and SD-1 sample preparation modules that automate the upstream polymer dissolution workflow, plus recalibration and contract polymer testing services. Customer end-markets span polymer manufacturers, compounders, extruders and recyclers, petrochemical and lubricant labs, pulp and paper producers, pharmaceutical/cosmetic manufacturers (notably hyaluronic acid), and electrical paper/insulation producers, with 1,300+ cumulative clients across 57 countries. PSL operates a direct-to-customer go-to-market combining a technical sales team, a proprietary multi-region e-commerce webshop, and a US regional dealer, with all UKAS-accredited calibrations performed in-house at the Essex reference laboratory.

Name

Poulten Selfe & Lee

Legal name

Poulten, Selfe & Lee Limited

Website

https://psl-rheotek.com

Company type

Private

Founded year

1850

Operating status

Operating

Headcount range

11–50 employees

Short description

Poulten Selfe & Lee (PSL Rheotek) is a UK-based specialist manufacturer, founded 1850, of calibrated glass capillary viscometers, constant-temperature baths, certified viscosity reference standards, and automated polymer viscometer systems. It serves polymer, petrochemical, pulp and paper, pharmaceutical, and electrical insulation laboratories across 57 countries, anchored by its UKAS ISO 17025 accredited primary viscosity scale.

Ownership category

akta.pro rank

Headquarters

HQ city

Granger

HQ country

United States

HQ region

North America

Offices3 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Operations, Supply Chain, Technology or R&D, Marketing or Sales

Revenue model

1. Hardware Sales - Glass Viscometers: Sale of calibrated glass capillary viscometers including Ubbelohde, Cannon-Fenske, U-tube reverse flow, Zeitfuchs Cross-Arm, and Suspended-Level types. Each supplied with UKAS calibration certificate.
2. Viscometer Baths and Accessories: Constant temperature viscometer baths (EVS, TCB series), viscometer holders, bath oils, and bench stands for temperature-controlled viscosity testing.
3. Automated Polymer Viscometer Systems: RPV series automated viscometers (RPV-1, RPV-3) with various configurations including 2 or 4 measuring positions, auto sampler options, and high-temperature variants for PP/PE testing.
4. Recalibration Services: ISO 17025 accredited recalibration services for glass capillary viscometers to maintain compliance with calibration interval requirements from auditors.
5. Polymer Testing Services: Contract testing services including IV of PET (ASTM D4603), K-Value of PVC (ISO 1628-2), Limiting viscosity of pulp (ISO 5351), Viscosity Number of Polyamide (ISO 307).

Pricing tiers

Go-to-market motion2 records

Distribution channels4 records

Marketing channels5 records

Core offering

Poulten Selfe & Lee (trading as PSL Rheotek) manufactures and calibrates capillary viscometry equipment, including glass capillary viscometers, automated polymer viscometer systems, constant temperature viscometer baths, and certified viscosity reference standards. All viscometers are supplied with UKAS ISO 17025 certificates of calibration directly traceable to the company's own primary viscosity scale. The company also provides custom viscometer solutions, UKAS-accredited recalibration services, and contract polymer testing for industrial customers.

Product overview

Poulten Selfe & Lee (trading as PSL Rheotek) is a specialist manufacturer of capillary viscometry equipment based in Essex, England. The product portfolio centers on glass capillary viscometers (Ubbelohde, Cannon-Fenske, U-Tube, Zeitfuchs, and Suspended-Level designs) and automated polymer viscometer systems (RPV-1 and RPV-3). These are complemented by constant temperature viscometer baths, viscosity reference standards, sample preparation modules (iSP-1, iSP-2), and accessories. The company offers UKAS ISO 17025 accredited calibration services and contract polymer testing. All viscometers are calibrated traceable to the company's own primary viscosity scale maintained at its reference laboratory.

Differentiator

Problem solved

Functional benefit

Products and services

• Glass Capillary Viscometers Precision glass capillary viscometers for measuring kinematic viscosity of transparent and opaque liquids, including Ubbelohde, Cannon-Fenske Routine, Cannon-Fenske Opaque, U-Tube, U-Tube Reverse Flow, Zeitfuchs Cross-Arm, and Suspended-Level Shortened Form designs. All units are supplied with a UKAS (ISO 17025) Certificate of Calibration directly traceable to the PSL primary viscosity scale, intended for polymer, petrochemical, pulp and paper, and pharmaceutical QC laboratories.
• Viscometer Baths
• RPV-3 Automated Polymer Viscometer Automated viscometer system for intrinsic viscosity (IV) testing of polymers in dilute solution. Automates sample elevation, resting, release, flow time detection, result calculation, cleaning, and drying. Compliant with ASTM D4603, ISO 1628 parts 1-5, IEC 60450, and ASTM D2857, available in 2 or 4 measuring positions for polymer QC laboratories.
• RPV-1 Automated Polymer Viscometer Automated viscometer for measuring intrinsic viscosity of polymers including PET, rPET, PBT, and polyamide. Supports compliance with ASTM D4603 and ISO 1628. Available with auto sampler configuration for high-throughput polymer laboratories.
• iSP-1 Integrated Polymer Sample Preparation Automated sample preparation module for polymer viscometry that simplifies the dissolution and preparation of polymer samples prior to intrinsic viscosity measurement, sold as a standalone product compatible with PSL Rheotek automated viscometer systems.
• iSP-2 PULP Integrated Sample Preparation Sample preparation module designed specifically for pulp and cellulose viscosity testing workflows, sold as a standalone product to automate the sample preparation step for limiting viscosity number testing of pulp.
• SD-1 Sample Dissolution Block Heated block for dissolving polymer samples in appropriate solvents prior to viscosity measurement, sold as a standalone product for polymer QC and R&D laboratories.
• WAS-1 Wrist Action Shaker Wrist action shaker for agitating polymer-solvent mixtures during sample dissolution for viscosity testing, sold as a standalone product for polymer QC laboratories.
• Viscosity Reference Standards Certified viscosity oil standards used to verify and calibrate viscometers. All standards are supplied with certified kinematic and dynamic values directly traceable to the primary viscosity scale (double distilled water at 20 °C = 1.0034 cSt), supporting ongoing QC verification of viscometer performance.
• Glass Viscometer Recalibration Services ISO 17025 accredited recalibration of glass capillary viscometers, issued with a UKAS certificate from Laboratory No. 0247, enabling laboratories to comply with calibration interval requirements imposed by auditors.
• Polymer Testing Services Contract viscosity testing services covering IV of PET (ASTM D4603), K-Value of PVC (ISO 1628-2 / ASTM D1243), Limiting Viscosity of Pulp (ISO 5351), and Viscosity Number of Polyamide (ISO 307), offered to manufacturers and laboratories that need outsourced testing.

Quantifiable outcome

• Most automated measurements complete within approximately 26-30 minutes
• +3 more outcomes

Named customers5 records

Segments5 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Scale indicators4 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Anton Paar: Anton Paar manufactures rotational rheometers (MCR series), SVM kinematic viscometers, and high-throughput polymer characterization instruments. Competes directly in polymer IV and kinematic viscosity testing and is the most credible alternative supplier for large polymer manufacturers evaluating PSL's RPV platform.
• Hydramotion: Hydramotion manufactures inline and laboratory viscometers for process and QC applications across chemicals, food, and oil. A direct peer in the viscometer-manufacturer category, though typically focused on process/online viscosity rather than capillary laboratory measurements.
• TA Instruments (Waters): TA Instruments supplies rheometers, viscometers, and thermal analysis instruments used in polymer R&D and QC. Their rotational rheometers are an alternative platform for IV and K-value testing and represent a long-term substitute risk for PSL's capillary-based automated systems.
• Brookfield Engineering (AMETEK): Brookfield is a leading manufacturer of rotational viscometers and rheometers widely used in polymer, petrochemical, and coatings QC. Competes with PSL in the broader viscosity-measurement category and is increasingly used as an alternative to capillary methods for IV and K-value work, putting direct competitive pressure on PSL's automated polymer systems.
• Cannon Instrument Company: Cannon Instrument (now part of AMETEK) is the historical leader in glass capillary viscometers, viscosity standards, and constant-temperature baths. Directly competes with PSL on Ubbelohde, Cannon-Fenske, and reverse-flow viscometers, calibration services, and certified viscosity reference standards — overlapping essentially the entire PSL product line.
• Koehler Instrument Company: Koehler supplies petroleum testing instruments including kinematic viscosity baths, viscometers, and certified standards per ASTM D445. Directly overlaps with PSL's petrochemical/oil & gas customer base and competes on viscometer baths and reference standards in that vertical.

Regional players

• PAC (Petroleum Analyzer Company): PAC (formerly ISL/Phase Technology) supplies automated kinematic viscosity instruments and cold-flow analyzers for petroleum laboratories. Strong overlap with PSL's petrochemical/lubricant testing offering; serves a primarily oil & gas customer base with high-throughput automated viscometers.

Broad incumbents

• Thermo Fisher Scientific: Thermo Fisher's Materials & Structural Analysis division offers rheometers, viscometers, and polymer characterization instruments as part of a broad laboratory instrument portfolio. While not a specialist capillary-viscometer maker, it serves overlapping polymer and petrochemical QC customers with bundled instrument solutions.
• Agilent Technologies: Agilent provides chromatography, spectroscopy, and polymer characterization instruments used in polymer and chemical QC labs. Indirect competitor to PSL in the broader polymer analytics category; large labs may consolidate instrument vendors in PSL's customer base.
• Malvern Panalytical: Malvern Panalytical supplies materials characterization instruments including rheometers and particle size analyzers used in polymer and pharmaceutical labs. Represents a broad-incumbent threat in polymer IV and molecular-weight characterization workflows where PSL's automated capillary systems are deployed.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/psl-rheotek

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

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