Glass Viscometers
Precision glass capillary viscometers
Our glass viscometer range includes top-quality Cannon Fenske, Ubbelohde, and ball/bulb types—manufactured. All viscometers are manufactured according to ASTM and ISO standards. Each viscometer is calibrated in our UKAS accredited laboratory (ISO 17025).
Ideal for labs requiring precision in kinematic viscosity testing (ASTM, IP, ISO), each viscometer comes with an ISCO 17025 certificate-traceable calibration. Choose form factor, size, and flow constant tailored to your method and sample type.
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Glass Viscometers made in United Kingdom
Premium glass capillary viscometers – ISO 17025 certified & ready to ship Precision.
Reliability. Compliance. PSL Rheotek glass capillary viscometers are expertly crafted in Essex, UK, by master scientific glassblowers using high-grade borosilicate tubing. With nearly a century of expertise behind every instrument, we offer unmatched accuracy for laboratories that demand compliance with ASTM, ISO, and IP methods.
Place your order before 11 am UK time for next day shipping. No minimum order value.
Why choose PSL Rheotek glass viscometers?
● ISO 17025 certified calibration Included
Every viscometer is calibrated in our on-site ISO 17025-accredited laboratory (Lab No. 0247) and delivered with a fully traceable certificate. Calibration is performed directly against our Master Viscometer Scale for dependable, audit-ready results.
● Handcrafted precision
Our glass viscometers are hand-formed to exact tolerances for optimal measurement accuracy. Unlike mass-produced alternatives, each tube undergoes detailed inspection and validation to ensure consistent flow characteristics.
● Built for regulated labs
Trusted in petrochemical, pharmaceutical, polymer, and academic laboratories worldwide, PSL Rheotek viscometers are compatible with ASTM D445, ISO 3104, and EN 12596 methods.
Choosing the right viscometer for your application
● Transparent liquids → Use the ASTM Ubbelohde viscometer
✔ Temperature-independent constant
✔ Accurate with minimal sample volume
✔ Features atmospheric air arm for reliable flow
● Opaque or dark liquids → Use the U-Tube Reverse Flow Viscometer
✔ Backflow design avoids visibility issues
✔ Ideal for samples where the flow meniscus isn’t clearly visible A
ll common viscometer sizes are in stock and available for next-day dispatch.
Your pain points, solved
Problem: “We need traceable, standards-compliant results.”
Delivered with ISO 17025 calibration traceable to primary standards. “
Problem: Our last batch of viscometers had inconsistent flow times.”
Each unit is hand-calibrated against Master Reference tubes. “
Problem: Lead times from other suppliers are too long.”
Next-day shipping available for all standard sizes.
Problem: “We test both transparent and opaque samples.”
Wide selection of viscometer types to match your fluid properties and audit requirements.
Trusted worldwide for:
● Kinematic viscosity testing of fuels, lubricants, and oils
● Quality control in polymer manufacturing
● Compliance with global testing standards (ASTM, ISO, IP)
● University and research lab use
Don’t compromise on accuracy. Choose PSL Rheotek glass viscometers for certified, traceable, and long-term performance. Request a calibration consultation.
Which glass viscometer type should I use?
ASTM Ubbelohde for testing clear liquids and is easy to use. Cannon-Fenske Routine is also suitable for testing clear liquids, but is more difficult to use. BSU Reverse Flow is for opaque or black samples. Cannon Fenske Opaque can also be used for this.
What calibration documentation is included?
Many test methods specifically require the use of a glass capillary viscometer. The capillary viscometer is very accurate and has a wide range. A capillary viscometer is also reliable, simple to use and cost-effective.
How often should I recalibrate?
Your laboratory quality manual specifies recalibration intervals. This is typically 24 months. We recommend to monitor the calibration by running a certified visosity standard.
Can you supply Master Viscometers?
Yes, Master Viscometers are available from us. We have supplied numerous National Institutes of Metrology around the world with sets of Master Viscometers enabling them to set up a primary reference scale as per ASTM D2162.
Do you offer viscometer kits and holders?
Yes, accessories include holders, stop-watch, bench stands and many other useful accessories. Reach out to our sales team for a consultation to put together a kit for your requirement.