VAF instruments T-SENSE, Technical Manual

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7. OPERATING PRINCIPLES
7.1 GENERAL
A zero setting procedure is always necessary in order to obtain a correct measurement and reading.
For more detailed information see paragraph 6.4 in TIB 661 of the T-Sense
®
torque sensor.
The PEM4 touch screen is easy to operate and provides the operator with a standard selection of
torque, shaft speed and power data.
A number of conditional messages will inform you about error/fault conditions if applicable.
Setups determining functionality are only possible via the
access code 1234 .
All setups and computations are stored in a battery backup RAM. The PEM4 system is self-checking as
for correct functioning of its memories, program run and existence of supply voltage.
7.2 DISPLAYED PARAMETER AND ENGINEERING UNITS
The following parameters are available at the PEM4 touch screen:

Torque
(kNm)

Shaft speed
(rpm)

Shaft power
(kW)

Total energy
(kWh, MWh, GWh)

Time-base
(hours, minutes, seconds)
When a TT-Sense
®
Thrust & Torque measurement system is applied the PEM4 touch screen will
display below parameters in addition:

Propeller thrust
(kN)

Thrust power quotient
(kN/MW)
7.3 EXPLANATION OF THE PARAMETERS
7.3.1 Torque
The torque signal, measured in the rotor part, is sent wireless via the stator antenna to the electronics
in the control box. In this control box the signal is converted to a Ethernet, which signal is connected to
the PEM4 touch screen. Zero torque adjustment will be done during commissioning of the T-Sense
®
rotor and control box.
7.3.2 Shaft speed
The shaft speed is measured via a gravity sensor in the T-Sense
®
rotor part. This rotor part is
connected wireless to the stator electronics in the control box. The stator electronics are connected to
the PEM4 touch screen via Ethernet.
7.3.3 Power
The power is calculated by multiplying the above measured shaft speed and torque. The output values
are submitted to the PEM4 touch screen via the same Ethernet connection.
7.3.4 Thrust (option)
In case a TT-Sense
®
is installed, which additionally measures the axial displacement due to propeller
thrust, the thrust values are converted to an Ethernet signal in the same way as the torque and shaft
speed outputs.