Geosense HLC 6000 Series, Инструкция по эксплуатации

Страница: 20 / 26

20
V1.0 July 2020
7.0 MAINTENANCE
Geosense
®
HLC
-
6000 Series Hydraulic Anchor Load Cells are basically maintenance free
device for most applications but the following should be considered during the service life:
-
•
Keep away from direct sunlight to avoid large thermal affects
•
Keep the cable connection cap on when Readout not connected
•
Avoid any impacts or significant vibration which can damage internal sensors
•
Keep cables away from physical damage
•
Keep cable ends waterproof
8.0 TROUBLESHOOTING
Unexpected readings
The following are common scenarios which lead to the readings and performance of load cells
being questioned.
The reading taken on the Jack is taken at a different time from that taken on the load cell
The strand is tensioned using the jack, the locking collets are then replaced and the anchor left
to take the load. It is at this point the load on the installed permanent cell is read and does not
equate the load in the Jack prior to release. This is because of the Young ’ s modulus of the
anchor and all the slight play in the fixtures and fittings of the system that cause elasticity in the
system, it is the release of the stored energy in the system whilst transferring load to the
anchor and so at the same time through the load cell that cause this indifference. It is not the
fault of the load cell installed but merely a part of the stressing process that is overlooked due
to a lack of knowledge that trusting the instruments will help provide. It is recommended to
carry out Lift Off Testing for cell reading versus jack reading to identify any loss of load
transfer.
The use of a jack which is much longer than the squat load cells
This is more prone to inaccurate measurement of the loading due to eccentric loading causing
the system more likely to contain bending moment in the system and so likely to cause friction
between the ram and the seal, otherwise known as binding of the seal of the Jack. This will
cause the loading to be over registered by the Jack. Unfortunately this is often understood as
under registering load by the load cell. It is worth noting that each cell has been individually
calibrated before despatch and not touched since while the ram has probably been used on
site to install hundreds of anchors since its last cal date and so its calibration data must also be
viewed as less valid.