Temperature

The temperature controls allow you to view temperatures, select which temperature to control, and enter the temperature setpoint for the head.

• For leaf measurements, see Leaf chamber software controls
• For aquatic measurements, see Aquatic chamber software controls.

	The Temperature option turns the heat exchanger On or Off.
	Temperature measured in the console valve manifold.
	Temperature measured in the gas analyzers.
	Select this to control the heat exchanger temperature, then enter the setpoint.
	Select this to control chamber air temperature, then enter the setpoint.
	Select this to control leaf temperature, then enter the setpoint.
	Leaf temperature computed by energy balance.
	Quick adjust: Choose an increment (5, 1, or 0.1), then tap an arrow to adjust up or down by the selected increment.
	Representation of the head connector panel. The temperature source is T1 in this case.
	The Latching Buttons are visible when a second thermocouple is detected. These are described in greater detail in Support: LI-6800 Portable Photosynthesis System.

In this exercise we'll go through the settings to see the instrument respond.

1. Turn Temperature: On and then tap Txchg.
2. Observe the Txchg and Tair values in the display.
2. Enter a Setpoint of 25 °C or something that is a few degrees different from the current measured values.
3. The heat exchanger fan will turn on and the instrument will adjust to the new setpoint.
3. Next, tap Tair and enter a setpoint of 27 °C.
4. 
5. The instrument will adjust the heat exchanger until the air temperature is at the setpoint.
4. Now, set the Temperature Control to Leaf.
5. The instrument will adjust the heat exchanger until the leaf temperature measurement is at the setpoint.
5. Turn the temperature control off.