Suction Lysimeters

Description:

 

Suction lysimeters collect pore water from unsaturated soil. After installation below ground level, vacuum is applied to the lysimeter through tubing leading from the lysimeter to the ground surface. The negative air pressure created inside the lysimeter draws pore water into the lysimeter through the porous, stainless steel section of the lysimeter. The pore water is transported to the surface by applying positive pressure to the lysimeter through a second tube. At the surface the pore water is collected in a collection bottle. Suction lysimeters perform best in moist soil and below the water table. Pore water collection from relatively dry formations (pressure potential less than -500 mbar) is difficult.

 

 

Models:

 

SW-070-540  Dual Chamber

SW-071-260  Single Chamber

SW-074-8  Horizontal Small Single Chamber

SW-074-4  Small Single Camber

 

 

 

Features:

 

All welded 304 stainless steel construction

No glue or plastics

Suitable for organics and most inorganics

Separate upper chamber for sample storage (models SW-070 and SW-070A)

One way stainless steel valve prevents back flow from storage chamber to sample chamber (models SW-070 and SW-070A)

Strong and durable.

Suitable for installation at great depths (models SW-070 and SW-070A)

600 mbar bubbling pressure

Optional battery powered vacuum pump (SW-073)

 

 

 

Dual chamber models only:

 

Separate upper chamber for sample storage

One-way stainless steel valve prevents back flow from upper storage chamber to sample chamber

Suitable for installation at great depths

 

 

 

Accessories

Lysimeter SW-074

 

The small single chamber lysimeter is recommended for sampling down to approximately 5 feet (1.5 m). It has a bubbling pressure of 700 mbar.

 

One of the two 1/8" OD stainless steel outlets can be connected with tubing to a vacuum source, with a collection bottle in between. Vacuum can be supplied with the battery powered vacuum pump from Soil Measurement Systems (Model SW-073).

 

For moist soil the optimal vacuum is about 300 mbar, but higher levels of vacuum may be used. The partial vacuum draws the fluid through the porous stainless steel walls of the lysimeter and up into a collection bottle.

 

The second outlet is opened at the end of sampling to empty the fluid lines. Sampling duration depends on the amount of sample required, the soil type, and the soil moisture content. Sampling times can vary from less than 1 hour in wet soil, to more than 1 day in drier soil.

 

Tubing, unions and clamps available from SMS.

 

 

Lysimeter SW-071

 

The single chamber lysimeter is recommended for sampling down to 10 ft (3 m).

 

During sample collection, a constant vacuum is applied to the lysimeter through the vacuum/pressure line, while keeping the fluid return line closed. For moist soil the optimal vacuum is about 300 mbar. Vacuum can be supplied with the battery powered vacuum pump from Soil Measurement Systems (Model SW-073). The partial vacuum in the lysimeter draws pore water into the lysimeter through the porous stainless steel walls of the upper part of the lysimeter. The fluid is brought to the surface by applying positive pressure to the vacuum/pressure line and opening the fluid return line. The applied pressure forces the fluid up to the surface and into a collection bottle. Sampling duration depends on the amount of sample required, the soil type, and the soil moisture content. Sampling times can vary from less than 1 hour in wet soil, to more than 1 day in drier soil.

Lysimeter SW-070

 

The dual chamber lysimeter is recommended for sampling unsaturated or saturated materials at depths greater than10 feet (3 m).

 

During sampling, vacuum is applied to the vacuum/pressure line, while keeping the fluid return line closed. For moist soil the optimum vacuum is about 300 mbar. Vacuum can be supplied with the battery powered vacuum pump from Soil Measurement Systems (Model SW-073). The partial vacuum in the lysimeter draws pore water into the lower chamber of the lysimeter through its porous stainless steel walls. From there it is drawn into the upper chamber where it is stored. The fluid is brought to the surface by applying positive pressure to the vacuum/pressure line and opening the fluid return line, forcing the fluid up to the surface and into a collection bottle. A stainless steel check valve prevents back flow of the fluid from the upper chamber into the lower chamber and the soil around the lysimeter. Sampling duration depends on the amount of sample required, the soil type, and the soil moisture content. Sampling times can vary from less than 1 hour in wet soil, to more than 1 day in drier soil.

 

 

 

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