RST Instruments VW2100-DP - Default Chapter; Table of Contents

VW2100 Vibrating Wire Piezometer
Instruction Manual
ELM0005P
RST Instruments Ltd.
Page iii
TABLE OF CONTENTS
1 INTRODUCTION ............................................................................................................ 5
1.1 Model VW2100 ................................................................................................. 6
1.2 Model VW2100-DP ........................................................................................... 6
2 VIBRATING WIRE PRINCIPLE ........................................................................................ 6
3 CALIBRATION .............................................................................................................. 7
3.1 Field Calibration Check ..................................................................................... 8
4 READING PROCEDURES ............................................................................................... 9
4.1 VW Instrument Readings .................................................................................. 9
4.2 Initial Inspection and Check Readings............................................................... 9
4.3 Initial Readings ................................................................................................. 9
4.4 Pressure Equation (Using the VW2106 Readout) ........................................... 11
4.4.1 Linear Equation ..................................................................................... 11
4.4.2 Second Order Polynomial Equation ...................................................... 12
5 INSTALLATION ........................................................................................................... 13
5.1 Filter Saturation ............................................................................................... 14
5.2 Low Air Entry Sintered Stainless-Steel Filters ................................................. 14
5.3 High Air Entry Ceramic Filters ......................................................................... 15
5.3.1 One Bar High Air Entry Filters ............................................................... 15
5.3.2 Two Bar (or Higher) High Air Entry Filters ............................................. 16
5.4 Installation in Full ............................................................................................ 17
5.4.1 Compacted Clay ................................................................................... 17
5.4.2 Granular Materials ................................................................................ 17
5.5 Installation in Boreholes .................................................................................. 18
5.5.1 Sand/Bentonite Method......................................................................... 18
5.5.2 Fully Grouted Method ........................................................................... 20
5.6 Piezometers Drive In Soft Ground ................................................................... 22
5.6.1 Installation............................................................................................. 22
5.7 Cable Identification ......................................................................................... 23
5.8 Cable Routing ................................................................................................. 23
5.8.1 Transition from Vertical Borehole to Horizontal Trench ......................... 23
5.8.2 Horizontal Cable Runs .......................................................................... 23
5.9 Lightning Protection ........................................................................................ 24
6 TROUBLESHOOTING .................................................................................................. 25
6.1 VW Piezometer Fails to Give a Reading ......................................................... 25
6.2 VW Piezometer Reading Unstable .................................................................. 25
6.3 Thermistor Reading is Too Low ...................................................................... 26
6.4 Thermistor Reading is Too High ...................................................................... 26
7 SPECIFICATIONS........................................................................................................ 27
8 SERVICE AND REPAIR ................................................................................................ 28
APPENDIX A : VW2100 CALIBRATION SHEET ................................................................... 29