Cambridge Viscosity Blog

CVI launches the ViscoLab PVT+ for Hi-Temp, Hi-Pressure Applications

Aug 12, 2021 3:37:55 PM / by Patrick Riley

pvt_system_smallThe ViscoLab PVT+ is the latest in PVT technology by Cambridge Viscosity. This small-yet-powerful viscometer features a touchscreen interface with customizable functions to ensure fast access to the right information. Traditional PVT units, which include a laptop, pressure transducer, hub, air bath, and electronics, take up valuable workspace. The ViscoLab PVT+ is designed for the needs of the laboratory. It combines the user interface, pressure transducer, hub, and electronics in a single, compact enclosure. When mobility is a requirement, the PVT+ fits on a 30”x40” cart, and can be easily transported to other areas or laboratories. Plus, it has a low torque ceiling for easy assembly or disassembly.

With the ability to measure seven unique parameters, PVT+ delivers higher levels of functionality, compared to any other PVT viscometer on the market.

  • Viscosity
  • Pressure
  • Temperature
  • Temperature-compensated viscosity
  • Pressure-compensated viscosity
  • Density
  • PVT

Wider Piston Ranges

Piston ranges in the PVT+ are at a 50-1 span. The span a single piston can cover is 20cP to 1000cP. The wider piston range means you need to change the pistons less often. Viscosity changes as pressure and temperature change. When conditions change beyond the range that a piston can measure, it is necessary to stop the test and change the piston to one that is specified for the particular pressure or temperature. With each change, the system must be cooled, cleaned, and purged, the pistons are changed, the system needs to be brought back up to temperature. This is extremely time-intensive and takes about three hours. Wider ranges allow pistons to be changed more infrequently, which saves valuable lab time.

Rapid Thermal Stability

The ViscoLab PVT+ features rapid thermal stability within the temperature control system – which supports the fast return to temperature after system shutdown. With rapid thermal stability, PVT+ can return to temperature in 45 minutes, as opposed to the three hours a traditional system requires.

Automated Testing

The PVT+ allows users to design and implement unique testing protocols at different temperatures, which can be triggered to start automatically based on conditional variables. This is ideal for applications requiring frequent testing of the same sample, where requirements do not change frequently. This saves valuable set up time, allowing common tests to automatically run free from technician intervention.

Sample Stability

Sample degradation can be a result of many things – general handling, changing temperatures and pressures, settling, etc., and when it happens, it can affect viscosity readings. The ViscoLab PVT+ ensures sample stability before it reports the results. The viscometer is programed to receive 20 consecutive readings where the change in viscosity, temperature, and pressure readings are within a user-selectable threshold. This reduces the impact of operator error on viscosity data and ensures a stable sample reading.

User-Friendly Interface

The re-designed user interface has a built-in touchscreen, designed for superior functionality, as well as ease of use. The home screen can be fully customized, so you see the variables that are important to your work. Full-color graphs are also customizable as well as scalable, so you can configure them to your particular parameters. It offers an analog input to read and send data to a separate analog device, such as a flowmeter or a densitometer. Levels of authority can be set up with passwords to prevent unauthorized users from making changes to the instrument. Alarms offer a safeguard to warn users before the tests go beyond the parameters of the pressure vessel. The PVT+ is truly the most user-friendly, custom-engineered viscometer on the market.

Calibration Stability

Cambridge viscometers hold calibration for years. They are extremely stable instruments, and the ViscoLab PVT+ is no exception. This is because the patented oscillating piston design doesn’t include vibrating wires or other elements that get knocked around during normal operation. When calibration is required, the PVT+ can be calibrated by the user through the user interface – it doesn’t need to be sent back to the factory. This saves time and money, because it can be done quickly, right in the lab by your own technicians. 

Multiple Bath Fluids

The ViscoLab PVT+ accommodates many types of bath fluids. It can even be used for corrosive materials, since all wetted parts are made of the high-strength, corrosion-resistant Hastelloy and Inconel alloys.

Historical Data

With five gigabytes of memory and a built-in database, the ViscoLab PVT+ maintains historical records for well over a year of daily test runs. Test data can be exported as an Excel (.xcl) or comma separated value (.csv) file.


  • Viscosity Range: 0.2 cP – 20,000+ cP
  • Pressure Range: 43,000+ psi
  • Temperature Range: Up to 315°C (599°F)
  • Sample Size: < 6mL
  • Wetted Parts: Stainless Steel, Inconel, and Hastelloy



The ViscoLab PVT+ is designed for the needs of a busy lab environment. It is easy to use and highly customizable, and it incorporates six measurement parameters to capture a wide range of actionable data. With broader specifications and a rugged design, the PVT+ is tough enough to handle severe-service applications. Ideal for applications where fluids undergo high pressure or temperatures, the ViscoLab PVT+ is commonly used in reservoir and fluid analysis, compressor applications where lubricants experience high pressures and temperatures in bearings, in R&D labs at universities, and for any applications where you need to understand how liquids perform under extreme conditions.

Learn more about the ViscoLab PVT+

Tags: high temperature viscometer, viscosity measuring solution, ViscoLab PVT+

Patrick Riley

Written by Patrick Riley

Vice President of Process Analytics

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