Open Top Chamber (OTC) Technology
The purpose of Open Top Chamber (OTCs) is to study response of plants in high CO2 and other gas in environment with precise control and regulation of desired CO2, Temp and humidity inside the OTCs. Open Top Chambers (OTCs) is an innovative and cost effective approach to investigate effects of elevated CO2, Temperature and Humidity on the growth dynamics and yield response of plants. In this approach, CO2 gas is supplied to the chambers through CO2 gas cylinders and maintained at set levels using manifold gas regulators, pressure pipelines, solenoid valves,sampler, pump, CO2 analyzer, PC linked supervisory control and data acquisition (SCADA). The data generated by OTCs are more realistic for impact assessment analysis of rising atmospheric CO2 and temperature on plants for developing models to predict the responses for future climatic conditions. The accuracy of the results depends on the system adopted and its maintenance of the required CO2 levels with near natural and variable conditions for other parameters.
STRUCTURAL DESIGN OF A TYPICAL OPEN TOP CHAMBER (OTC)
Open Top Chambers for elevated CO2 study are built with high quality multi layered Polycarbonate sheets (4mm thickness) of 3X3X4mt. dimensions with GI/MS structure with proper foundation and grouting. A suitable door of 6ft X3 ft. size is provided in each chamber. Multiwall clear polycarbonate sheet with 80-85% light transmission level is used for OTC structure. Flat and angle aluminum and rust free screws are used for mounting of polycarbonate sheet. Welding at four corners and inclination of 30° at top is provided to protect against high winds and moderate vibrations. Sealing of OTC is achieved using aluminum angles, plates at the top, corners and center along with gaskets. Door is sealed using “U” type gaskets with overlapping of sheets to prevent loss of CO2.