CMG-3V
Contents
1 Introduction...........................................................................................................................4
1.1 System confguration.................................................................................................... 5
1.2 Digital borehole installations.......................................................................................6
1.3 The hole lock system.....................................................................................................7
The three-jaw hole lock..................................................................................................7
The single-jaw hole lock.................................................................................................8
2 First encounters...................................................................................................................10
2.1 Unpacking and packing..............................................................................................10
2.2 Handling notes.............................................................................................................10
2.3 Assembling the 3V.......................................................................................................11
2.4 Control units................................................................................................................ 12
The surface control unit............................................................................................... 12
The handheld control unit...........................................................................................16
The inclinometer monitor unit....................................................................................17
2.5 Operating the hole lock.............................................................................................. 19
Engaging the hole lock.................................................................................................20
Disengaging the hole lock........................................................................................... 21
Manual operation......................................................................................................... 21
3 Installing the 3V in a borehole........................................................................................ 22
3.1 Installing a sensor with hole lock unit......................................................................22
3.2 Installing a sensor using sand backfll......................................................................27
Procedure.......................................................................................................................28
3.3 Assembling the winch.................................................................................................32
3.4 Earthing a borehole sensor.........................................................................................38
Installations with AC power supplies........................................................................38
Installations with DC power supplies....................................................................... 42
External lightning protection...................................................................................... 43
3.5 Levelling and centring................................................................................................ 44
4 Calibrating the 3V..............................................................................................................46
4.1 Calibration methods....................................................................................................46
4.2 Calibration with Scream! ...........................................................................................47
4.3 Calibration with a handheld control unit................................................................ 48
4.4 The coil constant.......................................................................................................... 49
5 Inside the 3V....................................................................................................................... 50
5.1 The sensor.....................................................................................................................50
5.2 The control system...................................................................................................... 52
LOCK .............................................................................................................................52
UNLOCK ...................................................................................................................... 53
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