Real reactors do not satisfy the idealized flow patterns, back mix flow or plug flow deviation from ideality can be due to channeling of fluid through the vessel, recycling of fluid within the vessel or due to the presence of stagnant region or pockets of fluid in the vessel. To predict the exact behaviour of a vessel as a Chemicals reactor, RTD or stimulus response technique is used.The setup consists of one feed tank through which water is fed to the reactor. The flow rate can be adjusted by operating the needle valve and measured by Rotameter. The compressed air is used for circulation of feed. The continuously stirred tank reactor made of Stainless Steel is provided for understanding the R.T.D. characteristics. Pressure Regulator & Pressure Gauge are fitted in the compressed air line.