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Carlson Soil Stress Cell (left) and the Carlson Concrete Stress Cell (right)
Carlson Soil Stress Cell (left) and the Carlson Concrete Stress Cell (right)
Close-up of the Carlson Concrete Stress Cell Close-up of the Carlson Soil Stress Cell

CARLSON STRESS CELLS

CATEGORY > Carlson Instruments

CARLSON STRESS CELLS

DESCRIPTION

Carlson Stress Cells are 178 mm (7 in.) diameter plates with a strain-meter sensing element mounted on one face. The plate has a mercury film at its mid-thickness and a flexible rim with the result that any stress through the plate is applied to the mercury film. Extraneous deformation such as drying shrinkage have very little effect on stress through the plate (and the mercury) so the calibration is in terms of compressive stress per 0.01 per cent reduction in the resistance ratio of the sensing element. The sensing element is isolated from the concrete by having a free space around it. A thin walled PVC tube is attached to the main diaphragm in such a way that it surrounds the sensing element, but does not touch it.

The stress cell may properly be called an “inter-face” stress meter because it is adapted to the measurement of compressive stress against a surface. It is similar to the stress meter for concrete, but it has a much thicker plate to make it independent of the distribution of force against it. Although it is intended mainly for the measurement of soil pressure against a surface, it can be used wherever it is desired to measure force with minimum deformation. The deformation required to produce one least reading of force is less than one millionth of an inch. This is accomplished by having an internal diaphragm which is small compared to the whole plate, and it is the deflection of this small diaphragm by the strain-meter sensing element which constitutes the measurement of force against the larger plate.

Flexibility of the rim is obtained through the use of grooves in such a way that there is no unloaded ring at the outer edge as in the case of the concrete stress meter. Thus, this stress cell can be mounted in a concrete wall, for example, so that the bottom face is flush with the surface of the concrete and then the stress cell acts as a part of the wall. It is fully responsive to pressure without altering that pressure during measurement.

QUICK SPECS

May be called an "interface" stress meter.

APPLICATIONS

Measures soil pressure against a surface.


Measures force with minimal deformation.

BENEFITS

Increase Productivity


High Accuracy


High Reliability

DESCRIPTION

Carlson Stress Cells are 178 mm (7 in.) diameter plates with a strain-meter sensing element mounted on one face. The plate has a mercury film at its mid-thickness and a flexible rim with the result that any stress through the plate is applied to the mercury film. Extraneous deformation such as drying shrinkage have very little effect on stress through the plate (and the mercury) so the calibration is in terms of compressive stress per 0.01 per cent reduction in the resistance ratio of the sensing element. The sensing element is isolated from the concrete by having a free space around it. A thin walled PVC tube is attached to the main diaphragm in such a way that it surrounds the sensing element, but does not touch it.

The stress cell may properly be called an “inter-face” stress meter because it is adapted to the measurement of compressive stress against a surface. It is similar to the stress meter for concrete, but it has a much thicker plate to make it independent of the distribution of force against it. Although it is intended mainly for the measurement of soil pressure against a surface, it can be used wherever it is desired to measure force with minimum deformation. The deformation required to produce one least reading of force is less than one millionth of an inch. This is accomplished by having an internal diaphragm which is small compared to the whole plate, and it is the deflection of this small diaphragm by the strain-meter sensing element which constitutes the measurement of force against the larger plate.

Flexibility of the rim is obtained through the use of grooves in such a way that there is no unloaded ring at the outer edge as in the case of the concrete stress meter. Thus, this stress cell can be mounted in a concrete wall, for example, so that the bottom face is flush with the surface of the concrete and then the stress cell acts as a part of the wall. It is fully responsive to pressure without altering that pressure during measurement.

QUICK SPECS

May be called an "interface" stress meter.

APPLICATIONS

Measures soil pressure against a surface.


Measures force with minimal deformation.

BENEFITS

Increase Productivity


High Accuracy


High Reliability

CONTACT US

RST Instruments Ltd.

11545 Kingston Street
Maple Ridge, BC
Canada V2X 0Z5

604-540-1100

1-800-665-5599

Fax: 604-540-1005

info@rstinstruments.com

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ASK A QUESTION

CONTACT US

RST Instruments Ltd.

11545 Kingston Street
Maple Ridge, BC
Canada V2X 0Z5

604-540-1100

1-800-665-5599

Fax: 604-540-1005

info@rstinstruments.com



CONNECT WITH RST

Linkedin icon
Youtube icon

ASK A QUESTION

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