The Herzog HVU is an automatic Ubbelohde viscometer that uses standard Ubbelohde capillary tubes and a highly stable temperature control system. It is suitable for laboratories that require accurate test results in accordance with ASTM and ISO standards. 

The instrument can test up to 2 samples at the same time using Ubbelohde capillary tubes. Users can select either a Near-Infrared (NIR) liquid level detection system or a Thermal NTC detection system based on the type of sample. These systems accurately detect liquid flow and measure flow time for viscosity calculation. 

The HVU Series is available in 2 models: 

HVU 481: Temperature range from 20 to 150°C. Suitable for viscosity testing of oils and lubricants at medium to high temperatures. 

HVU 482: Temperature range from -40 to 100°C. Suitable for aviation fuels and other samples that require low-temperature testing. 

The temperature control system provides stability of ±0.01°C. This helps samples reach temperature balance quickly and keeps the test conditions stable. The instrument also includes an automatic capillary cleaning system with Kalrez™ seals. These seals are resistant to strong solvents such as toluene and acetone. 

A complete test cycle, including automatic cleaning, takes approximately 30–40 minutes. 

Test results can be displayed on the instrument screen and sent to a printer or LIMS. Users can easily store, check, and review sample information, capillary tube information, test parameters, and previous test results.