Photosynthesis, Plant Respiration & Transpiration

Q-CO650 Plant CO2 Analysis Package. The system is designed to measure photosynthesis, respiration and transpiration in leaves when placed in a temperature controlled flow-through leaf chamber. The Plant CO2 Package can be used in the laboratory or in the field (with an optional battery pack). The Q-CO650 software automatically checks the reference levels of CO2 and water vapour and provides on-the-spot calculations of photosynthesis and transpiration rates. Applications include: Photosynthetic CO2 exchange rate, transpiration rate, water use efficiency studies, dark respiration, leaf, root and whole plant studies (roots and whole plants with optional ecosystem respiration chambers), and soil respiration or animal respirometry (with additional components).

The Q-CO650 Plant CO2 Analysis Package uses a single infrared CO2 gas analyser (Q-S151). This analyser measures the concentration of CO2 gas entering and leaving a leaf chamber at different intervals. The user has control of the solenoid valve assembly, allowing alternation between reference and sample measurements. During light exposure, the package calculates the rate of photosynthetic CO2 fixation by analysing the difference between the influx and efflux CO2 levels (differential CO2) and taking into account the gas flow through the chamber. In the absence of light, CO2 exchange measurements provide valuable data on dark respiration. Continue reading

The Q-A113 LED Light delivers photosynthetically active radiation (PAR) to the leaf with minimal heat generation. This light source can deliver a maximum output of approximately 2000 µmol photons m-2 s-1 and is pre-calibrated in the software. This allows precise adjustment of light intensity without the need for a light meter. For leaf conductance calculations, the Q-S1730 Leaf Thermistor, located in the lower part of the leaf chamber, is essential. The Q-G1120 flow-through leaf chamber is equipped with temperature control. All analogue signals from the sensors are converted to digital signals via three built-in LabQuest mini interfaces, providing a total of nine channels. Data can be viewed, recorded and manipulated on a PC or MAC computer using Logger Pro software.

The Q-Box CO650 contains a humidity/ temperature sensor (Q-S161) that measures the relative humidity of the air before and after it passes through the leaf chamber. At the same time, the temperature at the rH sensor is also recorded. The difference in relative humidity between the incoming and outgoing gas, together with temperature, flow rate (through the leaf chamber) and leaf temperature, allows calculating transpiration rates. Each photosynthesis package includes customised experiment files to facilitate data collection, automated calculations and further analysis.

Q-FL23 Suspension CO2 Analysis Package,  measures the CO2 exchange of algae, bacteria or fungi (or any kind of liquid suspensions incl. water samples) in the headspace of a cuvette. The CO2 gas released from the suspension into the headspace of the cuvette is dried and transferred to the Q-S151 CO2 analyser for measurement of CO2 levels (0-2000 ppm) in a flow-through system. Applications include algal photosynthesis, fermentation studies, biological activity of water samples, etc.