PSF‐1.5cSt Low Temperature Heat Transfer Fluid is a clear, colorless and odorless low‐ viscosity linear Polydimethylsiloxane that is formulated as a cold and heat transfer medium in a wide range of applications. PSF‐1.5cSt Silicone Heat Transfer Fluid has an operating service temperature range of –70oC to 120oC (closed system only*).    PSF‐1.5cSt Silicone Heat Transfer Fluid is characterized by its low pour points, low temperature stability, wide service temperature range, low viscosity change at temperature (low V.T.C.), low surface tension, long service life, and hydrophobic nature (insoluble in water).    PSF‐1.5cSt Silicone Heat Transfer Fluid has a Thermal Conductivity value of   0.00025 g cal/cm ?sec ?°C.  Its specific heat value is 0.410 cal/g/°C @ 25°C.   PSF‐1.5cSt has a low viscosity‐temperature coefficient or V.T.C. (viscosity @99°C ÷viscosity @ 38°C).    The lower the V.T.C., the lower the viscosity will be at lower temps.    Thus, its viscosity will not increase significantly even at extremely low temperatures.  For example, at –40°C, the viscosity of PSF‐1.5cSt is only 6cSt.  This is critical for baths that have pumping systems that cannot operate with higher viscosity fluids.