Testbourne silicone 4 has excellent oxidation resistance, very low vapour pressure, fast pumping speed, high mass throughput, temperature and chemical stability and low back streaming rate.This fluid can be used in all popular fluid vapour diffusion pumps, especially where other silicone fluids have been used previously. It will enable an appropriately engineered vacuum system to obtain base pressures to very high standards (circa 10-8 mbar) without the use of a cold trap, or ultra high vacuum (low 10-11 mbar) with a liquid nitrogen cooled trap.
Testbourne Silicone 4 is non-toxic and non-corrosive. It is also free from impurities and shows good resistance to radiation. Its excellent oxidation resistance allows accidental air admittance to a hot diffusion pump boiler with little chance of carbonisation taking place. The product will therefore give a long life and prove to be most economical.