LR-Cal TB 300-M
Stationary temperature calibration bath
+50...+300°C

Applications:

• Thermostatic fluids for micro baths and thermostatic temperature calibration baths

Main Characteristics:

• Operating range -50...+200°C
• High stability
• Good thermal conductivity
• Nearly odourless
• Long service live
• Packaged in bottle or canister
• Different types for a wide range applications
• Low toxicity
• Low viscosity and corrosovity

Our thermostatic fluids are suitable for use in liquid thermostatic calibrators and thermostatic baths for applications from -50°C to +200°C.
The choice of thermostatic fluid is the most important aspect for obtaining the best results with regard to operation and temperature control of calibrators and baths.
These fluids have perfect thermodynamic characteristics to guarantee the best performance in the various fields of application, ensuring safe and reliable operation as well as optimum heat transfer efficiency.
Silicone-based fluids are chemically inert substances that do not affect metals, are resistant to weathering and, when used correctly, the very low formation of cracking and oxidation ensures a long service life.

Most of our thermostatic fluids are available in different containers: 500 cm³ bottles or 9 kg canisters (25 kg on request).

Specific heat
The specific heat is the amount of heat required to raise or lower the temperature by 1 °C per kg. The specific heat, called CP, is expressed in Kcal/Kg °C. The energy required to heat or cool the calibration liquids depends on the amount of liquid contained in the calibrator in kg and its specific heat. A high specific heat value requires more energy to change the temperature, but offers greater temperature stability. The average CP of silicone fluids is 35 Kcal/Kg °C. The CP of water at 20 °C is equal to 1.

Thermal conductivity
Thermal conductivity is the ability of the liquid to transfer heat from one molecule to another. The better the heat transfer, the faster the liquid heats or cools. Better thermal conductivity improves the temperature uniformity in the reservoir of the calibration bath.

Expansion
All liquids have a coefficient of thermal expansion. This indicates how much the volume of a liquid changes (expands or contracts) when the temperature changes. Liquid expansion has an important impact on the safety, cleanliness and maintenance of temperature calibration baths. If calibrators are filled with too much liquid at a low temperature and then heated without regard to the increase in volume, they can overflow.

If too little liquid is filled in the reservoir, below the level of the heating elements, the temperature rise of the non-immersed part of the heating elements could ignite the liquid.

Gelation (polymerization)
The gelling temperature is the temperature at which silicone fluids oxidize, gel and turn into a viscous slurry. The main cause of this phenomenon is oxidation. Although silicone fluids can be used safely up to their flash point, the susceptibility to polymerization increases when used above their oxidation point. To prevent polymerization, it is advisable to keep the operating time above the oxidation point of the silicone oil used as short as possible in order to keep contaminants (salts, other oils and oxidizing agents) away. The calibration fluid must be replaced if it becomes dark, viscous or temperature unstable. It is important to limit the application time at high temperatures to prevent the oil from degrading and to extend its service life.