C4 pathway A pathway of carbon fixation, found most commonly in tropical plants that have high rates of growth and photosynthesis and that are adapted to high temperatures, strong light, low carbon dioxide levels, and low water supply. Its importance lies mainly in its reduction of photorespiration.
PT 100 RTD means Resistance temperature detector(RTD) of platinum with 100 ohms resistance at zero degree centigrade.
An RTD is a temperature sensor which measures temperature using the principle that the resistance of a metal changes with temperature. In practice, an electrical current is transmitted through a piece of metal (the RTD element or resistor) located in proximity to the area where temperature is to be measured.