Users’ Manual
EDS-71V/P Single point borehole extensometer
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NOTE:
For very deep hole, staged grouting may be necessary. It is always best to consult grouting
engineer at site and take his advice
NOTE:
Packer anchor does not require the borehole to be fully grouted. It is recommended to use a
hand grout pump for better control. It is important to pump water first to water saturate packer
geotextile sufficiently. Pump grout until pressure builds up sufficiently to around 400 to 500
kPa. Let pressure dissipate for a few minutes and then pump again till a distinct pressure is
felt. Recommend grout mixture is 1 part cement and 1 part water by weight. Kink and tape
grout tube to retain pressure and disconnect pump. Clean pump thoroughly.
3.3.18 Remove screws (24) and lock nuts (25). Remove reference plate (14) and centre pillar (13) Cut
and remove grout and vent tubes. Round edges of grout and vent tube with a hand file. Clean
reference head assembly properly. Reassemble reference plate with centre pillar to guide plate.
3.3.19 Remove guide plate (6).
3.3.20 Insert sensor (20) in flanged housing (5) taking care that the cable is carefully routed out to be
eventually connected to the junction box (23). Secure sensor to adopter cum guide plate (6) with
grub screws (8a) ensuring that tube face (refer to figure 3.1) is around 10 mm extended from face
of adopter cum guide plate (6).
NOTE:
Since only one sensor is being used therefore cable identification mark tagging is not required.
Pull shaft of sensor and assemble to connecting rod end with reference button (15), link plate
(16), sensor tightening nut (17) and locknut (18).
3.3.21 Screw in the sensor to connecting rod clearly noting position of extensometer ‘1’.
CAUTION:
Never rotate shaft of displacement sensor in respect to the outside body. This will permanently
damage the sensor. During installation pull or push or pull shaft only axially. A pin has been
provided at the end of displacement sensor that sits flush in a groove in sensor body. During
assembly operation and while using spanners for tightening, keep sensor in closed position
with pin seated inside groove such that no torque is exerted on its shaft and there is no
rotational movement.
CAUTION:
Do not use thread sealant on any thread while mounting the sensor as it may have to be
replaced at a later date.
3.3.22 Check displacement reading of sensor with model EDI-51V/EDI 53P read-out. Reading would be
around specified initial reading (refer to § 3.3.11). Set reading precisely by loosening respective
sensor with grub screws (8.a), repositioning sensor in adopter cum guide plate (6) and again
tightening grub screw.
3.3.23 Reset zero reading in EDI-51V/EDI 53P to final set position of sensor. Subsequent readings will
determine relative displacement between anchor and reference plate.
3.3.24 Take initial readings with help of depth micrometer. It is recommended to note date, time and
temperature while taking the initial reading.
NOTE:
A proper record
of depth readings with depth micrometer should be permanently maintained.
This is very important because sometimes it becomes necessary to verify the data from
electronic sensors.
3.3.25 Attach nipple (22) to socket of flanged housing and fix junction box assembly (23) with cable from
sensor routed to junction box.
3.3.26 Connect leads to respective connector pins in junction box.
NOTE:
For transmitting signals to observation room, 4 core, 6 core, 12 core or 20 core cables are
available from Encardio-rite.
