Guralp Systems CMG-3TB - Manual (Page 2)

CMG-3TB
Table of Contents
1 Introduction............................................................................................................... 4
1.1 System configuration.......................................................................................... 5
1.2 Digital borehole installations............................................................................. 6
1.3 The hole lock system.......................................................................................... 7
The single-jaw hole lock...................................................................................... 7
The three-jaw hole lock........................................................................................ 9
2 Assembling the instrument.................................................................................... 11
2.1 Unpacking and packing.................................................................................... 11
2.2 Handling notes.................................................................................................. 11
2.3 Assembling the 3TB.......................................................................................... 12
2.4 Disassembling the instrument.......................................................................... 16
2.5 Control units..................................................................................................... 17
The breakout box................................................................................................ 17
Calibration...................................................................................................... 18
Mass locking and unlocking.......................................................................... 19
Centring.......................................................................................................... 19
The handheld control unit................................................................................. 19
Connections.................................................................................................... 20
Signal meter................................................................................................... 20
Calibration and control.................................................................................. 21
Banana plugs.................................................................................................. 21
The inclinometer monitor unit.......................................................................... 21
2.6 Operating the hole lock.................................................................................... 22
Engaging the hole lock....................................................................................... 23
Disengaging the hole lock.................................................................................. 24
Manual operation............................................................................................... 24
3 Installing the 3TB in a borehole............................................................................. 26
3.1 Installing a sensor with hole lock unit............................................................. 26
3.2 Installing a sensor using sand backfill............................................................. 31
Procedure............................................................................................................ 32
3.3 Assembling the winch...................................................................................... 36
3.4 Earthing a borehole sensor............................................................................... 40
Installations with AC power supplies............................................................... 40
Installations with DC power supplies................................................................ 44
External lightning protection............................................................................. 45
3.5 Levelling and centring...................................................................................... 46
3.6 Downhole orientation....................................................................................... 47
2 Issue C