TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

Instrument ... used to measure water potential of plant leaves.  3, record 1, English, - pressure%20bomb

Record number: 1, Textual support number: 1 CONT

Simply put, the pressure chamber ... is just a device for applying air pressure to a leaf (or small shoot), where most of the leaf is inside the chamber but a small part of the leaf stem (the petiole) is exposed to the outside of the chamber through a seal. The amount of pressure that it takes to cause water to appear at the petiole tells you how much tension the leaf is experiencing on its water: a high value of pressure means a high value of tension and a high degree of water stress. The units of pressure most commonly used are the Bar (1 Bar = 14.5 pounds per square inch) and the megapascal (1 MPa = 10 bars).  4, record 1, English, - pressure%20bomb

Record number: 1, Textual support number: 2 CONT

How is water potential measured?...-Pressure bomb(pressure chamber) : measures [psi subscript w] of whole leaves, stems :-when a stem or leaf is cut off of a plant, the sap is sucked back into the xylem, since it is under tension;-the tissue is sealed inside a steel chamber, with the cut end protruding;-pressure is applied(using compressed nitrogen) until the sap is pushed back up to the top; this amount of pressure is equal but opposite to the [Psi subscript w] of the tissue.  5, record 1, English, - pressure%20bomb

Record number: 1, Textual support number: 1 OBS

There are different types of pressure chambers, some using a tank of high pressure gas, some using a hand-pump, but all work on the same basic principle and in most cases the operation and use of the different types of pressure chambers is identical.  4, record 1, English, - pressure%20bomb

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 DEF

[Instrument de] mesure de l'état hydrique [...]  4, record 1, French, - chambre%20%C3%A0%20pression

Record 1,  Textual support,  Spanish

Record 2,  Textual support,  English

Record number: 2, Textual support number: 1 CONT

Transpiration : The process by which water vapo(u) r passes from the foliage or other parts of a living plant to the atmosphere... The transpiration stream... refers to the upward passage of water and solutes within the plant(mainly via the xylem-constituting the xylem sap) from the roots to the leaves.  3, record 2, English, - transpiration%20stream

Record number: 2, Textual support number: 2 CONT

Since movement of the more mobile trace metals such as aluminium occurs in the transpiration stream, these elements can be expected to be concentrated near sites of evaporative loss of water, and hence build up in and around the guard and subsidiary cells of the stomates.  4, record 2, English, - transpiration%20stream

Record 2,  Textual support,  French

Record number: 2, Textual support number: 1 CONT

Notre première approche a été de comparer l'état hydrique et les échanges gazeux de plants de Douglas en pots, associés symbiotiquement à différents champignons, dans un substrat maintenu à la capacité au champ. Les mesures physiques ont été réalisées par les techniques suivantes : chambre portable d'assimilation Li-Cor pour le flux de transpiration et la photosynthèse nette; gravimétrie et micropsychromètres pour le potentiel hydrique du sol; bombe à pression de Shollander pour le potentiel hydrique interne des aiguilles et des rameaux.  2, record 2, French, - flux%20de%20transpiration

Record 2,  Textual support,  Spanish