HVU 481 & 482 Ubbelohde Viscometers / Thiết bị đo độ nhớt động học bán tự động

Viscosity is a very important characteristic of new and used lubricants, fuels, waxes and bitumen products, some

requiring measurement as high as 1500C. Jet fuel, hydraulic fluids, etc., require measurement at negative temperatures

as low as -400C. Many petroleum products, and some non-petroleum materials, are used as lubricants, and the correct

operation of the equipment depends upon the appropriate viscosity of the liquid being used. In addition, the viscosity

of many petroleum fuels is important for the estimation of optimum storage, handling, and operational conditions. Thus,

the accurate determination of viscosity is a very essential characteristic of many product specifications

The Herzog HVU 481/482 viscometers automate the determination of kinematic viscosity while meeting

requirements of ASTM D445. To ensure quick, accurate results, the HVU analyzers incorporate powerful

microprocessor temperature control (near-infrared or thermal timing) systems that exceed precision

requirements of standard methods, together with an automatic capillary tube cleaning system. Capable to

run 2 tests simultaneously, kinematic viscosity is measured within less than 30 minutes (cleaning

included) using standard ASTM D445 defined operation parameters.

ENHANCED BATH STABILITY AND WIDE APPLICATION RANGE MANAGEMENT

Each HVU481/482 has one ultra-stable bath for two Ubbelohde-type capillaries, using silicone oil as bath

liquid (18 liters). The bath has a glass front and internal illumination to allow convenient view of test in

process. Accuracy and uniformity of the bath temperature is within 0.01°C and better than requested by

ASTM D445. The temperature can be calibrated for 10 temperature points (temperatures between these

points are derived by interpolation). The HVU baths are designed with four 260W heaters to ensure fast

stabilization time during temperature changes and are protected against over temperature and high/low

liquid levels. The thermal volume expansion of the liquid is automatically compensated within the whole

temperature range.

The Herzog HVU481 operates with a bath temperature that can be user-programmed from +20° up to

150°C. From 40 to 150°C it operates without any external cooling (max ambient temperature 28 °C). Thanks

to the built-in cooling coil it can be operated down to 20°C with the support of an external chiller or a fresh

water source. The built-in cooling valve isolates the external chiller or fresh water source when cooling is

not necessary, allowing for operation down to 20°C. The bath temperature is measured with a 0.001°C

resolution control circuit.

The Herzog HVU482 operates with a bath temperature that can be programmed from –40° up to +100°C

and is the ideal solution for low temperature applications (such as aviation turbine fuels). Due to the

standard built in cooling coil it can be operated down to -40°C with the support of an external chiller unit.

The (accessory) cooling valve isolates the external chiller when cooling is not necessary and prevents

excessive bath heating against the cooler. The bath temperature is measured with a 0.0025°C resolution

control circuit.

SMART, VERSATILE AND USER-FRIENDLY OPERATION

In the stand-alone mode, the operator fills the capillary and presses start on the face of the instrument. The

LCD screen display shows real-time progress status:” equilibrating”, “measuring”, and “cleaning”, together

with the result and times recordings. Operators have the option of choosing from three customizable

programs for a variety of samples as well as two types of cleaning programs.

The Herzog HVU481 requires an external cooler to obtain temperatures lower than +50°C. Special drying

tubes using molecular sieve keep away the air humidity from the capillary tube and the bath oil.

The Herzog HVU482 requires an external cooling to obtain temperatures 40°C and lower. This can be

managed with cooling water or a circulation cooler.

Effective and Robust Cleaning and Drying Procedure

The Herzog HVU’ sophisticated cleaning system include cycle parameters for 2 different non-corrosive

solvents to be programmed and ensure the best cleaning and drying results. All ambient air used for drying

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is pre-dried in molecular sieve tubes. A built-in vacuum system pumps the solvents from the reservoirs to

the capillaries. The solvent containers are not pressurized and can be placed up to 5m below the HVU

481/482 systems. A built-in special slop sensor (detector sold separately) prevents the flooding of the

slop vessel and give an alarm message when full. The valve system uses Kalrez seals that withstand

nearly all aggressive solvents like Acetone or Toluene.

POWERFUL PC-BASED NETWORK AND DATA MANAGEMENT SYSTEM

Flexibility and expansion are at the heart of the Herzog HVU 481/482 systems. As your testing needs

expand and more different calculations necessary (VI, Energy, Gravity, SUS Saybolt and other), use the

Herzog Laboratory Information System (HLIS-32) Windows based PC program to easily interconnect up

to 16 HVU 481/482 viscometers then monitor and remotely control them. All test results can be collected

and stored in the HLIS-32 results database and analyzed for trends. From here they can be printed and /

or transferred to LIMS. This optional program gives the operator the flexibility to change cleaning programs

or setup profiles for various types of samples.

Note: HLIS-32 currently does not run on WindowsTM 10 OS.

Methods

ASTM D445, ASTM D446, IP 71, DIN 51 562, ISO 3104 test methods

Main Features

• Performs two tests simultaneously, in strict compliance to standard methods

• Ultra-precise near-infrared (NIR) or near-thermal conductivity (NTC) meniscus detection

• Flexible and robust design, for wide temperature application scope (down to -40°C; up to +150°C)

• Stand-alone operation or multi-instrument networking