First encounters
3.3
Levelling the instrument
The instrument must be physically level in order to operate correctly.
To level the instrument, first check the bubble level on the lid: the bubble should be
in the centre of the printed circle. If it is not, loosen the lock-nuts on the
instrument’s feet and then adjust the feet until the bubble is central.
Once levelled, secure the feet by screwing the lock-nuts downwards – not upwards –
as shown:
3.4
Zeroing the instrument
Before installing the 40T, you should check that the mass positions are not
significantly offset from zero. The 40T must be perfectly level for this to be effective.
The mass position offsets can be affected by any tilt to the instrument as well as
rough handling during transportation. The normal range of the mass positions is ±10
V; you should zero the instrument if any mass reads more than around ±3.5 V (>35%
of full scale) when the sensor is level and stationary.
The velocity outputs of the 40T are set at the factory to a nominal value below ±3 mV.
Once the instrument is installed and has reached thermal equilibrium with its
environment, these outputs should be similar to the factory-set value.
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Issue F - June 2019
