Stem / Leaf Water Potential Measurement

Stem / Leaf Water Potential Measurement

The roots of a plant use reverse osmotic forces to overcome the matrix potential of the soil. The stomates on the leaves of a plant transpire at different rates throughout the day. The resulting tension in the xylem column can be measured using a plant water status console device / water potential meter.

Using WP4C Water Potential Meter

Leaf water potential measurements are easily and accurately obtained using the chilled mirror dewpoint technique of the WP4C Water Potential Meter. The recommended procedure involves the abrasion of the leaf cuticle to speed equilibration.

Fast, Accurate Water Potential Measurements

Use the WP4C to measure water potential in 5 to 10 minutes.  Range: -0.1 to -300 MPa*WP4C-cutout

ACCURACY ±0.05 MPa* from 0 to -5 MPa
1% from -5 to -300 MPa
RANGE -0.1 to -300 MPa*
MEASUREMENT TIME In precise mode:

10-15 minutes for most soil samples

20 minutes for plant tissue samples

In fast mode:

<5 minutes (reduced accuracy)

TEMPERATURE CONTROL 15 to 40°C (± 0.2°C)
SENSOR TYPE 1) Chilled-mirror dewpoint sensor
2) Infrared temperature sensor
OPERATING ENVIRONMENT 5 to 40°C (41 to 104°F)
WARRANTY 1 year, parts and labor
SAMPLE CUP CAPACITY 7 mL recommended (15 mL full)
WEIGHT 3.2 kg (5.2 kg shipping weight)
DIMENSIONS 24.1 x 22.9 x 8.9 cm (9.5 x 9.0 x 3.5 in)
CASE MATERIAL Powder-painted aluminum
8-data bit ASCII code
9600 baud
no parity
1 stop bit
POWER 110 VAC to 220 VAC, 50/60 Hz
DISPLAY 20 x 2 alphanumeric dot-matrix LCD with backlighting
INTERFACE CABLE Standard RS232 serial cable (included)



The Plant Water Status Console / Scholander Bomb

A pressure bomb or pressure chamber or Scholander bomb is an instrument with which it is possible to measure the approximate water potential of plant tissues. A leaf attached to a stem is placed inside a sealed chamber and pressurised gas is added to the chamber slowly. As the pressure increases at some point sap will be forced out of the xylem and will be visible at the cut end of the stem. The pressure that is required to do so is equal and opposite to the water potential of the leaf.

Soilmoisture Equipment Corp. Manufactures variants of the apparatus to accurately observe the equilibrium value to be recorded and calls them the Plant Water Status Consoles.


The Compact Plant Water Status Console, comes complete with 5″ vessel and G4 specimen holder and will operate with a pressure range up to 40 bar. It is equipped with a quick-connect coupling to an air supply bottle. Ideal for field use because of its compact size (18.5″ x 14.5″ x 7″) and watertight housing.


The 3005 Series Plant Water Status Console provides a means of quickly and accurately measuring the water status of plant leaves.

Model 3005 is supplied with a pressurized gas tank, making it suitable for portable, field use. A solid polyethylene sample preparation board is mounted to the heavy-duty aluminum chassis. Sample chambers are available in several different lengths. Two operating pressure ranges, 0 to 40 bars and 0 to 80 bars, are available. Two specimen holders are available, one for use with round-stem materials, and one for blade-type plant materials. A number of differently sized and shaped sealing sleeves and grommets assure that the plant material of interest is safely sealed in the specimen holder, allowing measurements to be made.

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