This Series use liquid Nitrogen cooling (CO2 cooling on request) and utilise forced air recirculation.
The inner chamber is constructed from 316 stainless steel and insulated by high efficiency insulation. This durable stainless steel interioreliminates the risk of high temperature oxidation. A forced air skin heating/cooling system is incorporated to minimise skin temperatures when testing at high temperature. The outer case is constructed from mild steel with a durable grey finish.
Principle of Operation
The ETC Series of environmental chambers use forced air recirculation to promote optimum temperature uniformity with reduced thermal gradients in the region of the test specimen. Using a fan system that circulate hot or cold air around the specimen, grips and grip extensions to provide programmable heating & cooling rates and good thermal stability. The air is forced (forced convection) over a set of heating elements and enters the insulated test enclosure at top and bottom. This heated air is drawn back into the centre of the fan through a 'baffle plate' and is recirculated. The temperature of the heating elements is controlled via a type K thermocouple mounted in the centre of the baffle plate. For sub ambient operation, or where controlled cooling is required, liquid Nitrogen is injected into the recirculated air stream via a rear mounted solenoid valve controlled by a second channel on the temperature control instrument. A secondary impellor forces air between the inner insulation and the outer skin to minimise case temperatures when testing above ambient and minimise frosting when testing below ambient.