RST Instruments Push-In Pressure Cell User manual

RST INSTRUMENTS LTD.
11545 Kingston St.,
Maple Ridge, BC
CANADA V2X 0Z5
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LPM0032A
All efforts have been made to ensure the accuracy and
completeness of the information contained in this document. RST
Instruments Ltd reserves the right to change the information at any
time and assumes no liability for its accuracy.
Copyright © 2019. RST Instruments Ltd. All rights reserved.
Document Number: LPM0032A
Release Date: September 17, 2019
Push-In Pressure Cell
with Piezometer
Installation Manual

Push-In Pressure Cell with Piezometer
Installation Manual
LPM0032A
Page ii
REVISION HISTORY
Rev.
Revision History
Date
Prepared By
Approved By
A
Initial release.
2019-Sep-17
MP
AP

Push-In Pressure Cell with Piezometer
Installation Manual
LPM0032A
Page iii
TABLE OF CONTENTS
1 INTRODUCTION............................................................................................................1
2 SAFETY ......................................................................................................................1
3 FILTER SATURATION....................................................................................................1
4 INSTALLATION.............................................................................................................2
5 SERVICE AND REPAIR..................................................................................................3
LIST OF FIGURES
Figure 1-1 Push-In Pressure Cell with components....................................................................1
Figure 3-1 Filter set screw and filter...........................................................................................2
Figure 4-1 Typical Installation of a Push-In Pressure Cell..........................................................3

Push-In Pressure Cell with Piezometer
Installation Manual
LPM0032A
Page 1
1 INTRODUCTION
FIGURE 1-1 PUSH-IN PRESSURE CELL WITH COMPONENTS
The Push-In Pressure Cell is designed to be pushed into the ground where it can
measure total earth pressure and pore water pressure within soil. Typically, Push-In
Pressure Cells are installed in fine-grained cohesive soils, including very soft to stiff
clays.
2 SAFETY
The following callouts have been used throughout this document to highlight
important safety information:
WARNING: USED WHEN AN OPERATING PROCEDURE OR PRACTICE,IF NOT
CORRECTLY FOLLOWED,COULD RESULT IN PERSONAL INJURY OR LOSS OF LIFE.
CAUTION: USED WHEN AN OPERATING PROCEDURE OR PRACTICE,IF NOT STRICTLY
OBSERVED,COULD RESULT IN DAMAGE TO OR DESTRUCTION OF EQUIPMENT.
NOTE: USED TO HIGHLIGHT SPECIFIC NON-SAFETY RELATED INFORMATION.
3 FILTER SATURATION
The filter is intended to protect the delicate diaphragm area of the pressure
transducer while allowing transmission of pore water pressures. It must be saturated
prior to installation to allow the accurate transmission of hydraulic pressures to the
diaphragm.

Push-In Pressure Cell with Piezometer
Installation Manual
LPM0032A
Page 2
CAUTION: IF YOUR PUSH-IN PRESSURE CELL DOES NOT HAVE A PIEZOMETER,DO
NOT PROCEED WITH SATURATION.
The following steps outline the procedure for saturating the filter:
1Remove the filter set screw (Figure 3-1).
FIGURE 3-1 FILTER SET SCREW AND FILTER
CAUTION: TAKE CARE TO REMOVE ONLY THE FILTER SET SCREW.REMOVING THE
GLYCOL SET SCREW WILL DAMAGE THE PUSH-IN PRESSURE CELL.
2Submerge the Push-In Pressure Cell in a bucket of flat water (i.e. water that has
been sitting for 24 hours). This will fill the space above the diaphragm with water.
3Let the pressure cell sit in the water to completely saturate the filter.
4With the pressure cell submerged, slowly replace the filter set screw.
5The Push-In Pressure Cell should remain submerged until installation.
4 INSTALLATION
The following instructions outline the steps required to successfully install a Push-In
Pressure Cell:
1Drill a pilot hole slightly shorter than the planned installation depth.
2Connect the Push-In Pressure Cell to a readout. Take an initial reading.
3Carefully push the Pressure Cell into the pilot hole. Monitor the readout to ensure
the cell is not over-pressured.
CAUTION: MONITOR THE READOUT WHILE THE PRESSURE CELL IS BEING
INSTALLED TO PREVENT OVER-PRESSURING THE CELL.

Push-In Pressure Cell with Piezometer
Installation Manual
LPM0032A
Page 3
4Push the Pressure Cell about 1 meter past the bottom of the pilot hole using
standard drill rods or Cone Penetration Test (CPT) rods. The rods may either be
left in place or retrieved at a later stage after the measurements are completed.
NOTE: AN INVERSE THREAD ADAPTER ON THE CELL OR PUSH RODS TOGETHER WITH
A PUSH ADAPTER MAY ALSO BE USED IF THE CELL IS TO BE LEFT
PERMANENTLY IN PLACE.
FIGURE 4-1 TYPICAL INSTALLATION OF A PUSH-IN PRESSURE CELL
5 SERVICE AND REPAIR
The product contains no user-serviceable parts. Contact RST for product service or
repair not covered in this manual.