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.
BREAKING DOWN 'Heating Degree Day - HDD' To calculate HDD, take the average of a day's high and low temperatures and subtract from 65. For example, if the day's average temperature is 50 o F, its HDD is 15. If every day in a 30-day month had an average temperature of 50 o F, the month's HDD value would be 450 (15 x 30).