Safeline Signature, Operating And Instruction Manual

Page: 18 / 168

PRINCIPLES OF OPERATION
2 4618 - 021
PHASE VALUE
0 0
20 0 40 0 60 0 80 0
90 0
100
0
120
0
140
0
160
0
AMPLITUDE
STAINLESS
STEEL
FERROUS
NON-FERROUS
VIBRATION
180 0
VIBRATION
Fig 1 Phase/Amplitude
The characteristic of the phase control circuit is as
shown in Fig 2. This shows the position of the phase
control aligned to minimise the unwanted vibration
signal. All signals which break through the phase
control characteristic (the shaded area) will trigger the
detector. From this it can be seen that the amplitude
of the unwanted vibration signal would have to be
increased to trigger the detector.
It can be seen from Fig 2 that the phase control
characteristic masks off some of the ferrous signal
and has a minimal effect on the Non
Ferrous/Stainless Steel signals
PHASE VALUE
0
0
20
0
40
0
60
0
80
0
90
0
100
0
120
0
140
0
160
0
AMPLITUDE
STAINLESS
STEEL
FERROUS
NON-FERROUS
VIBRATION
180
0
VIBRATION
Fig 2 Effect of Phase Control
The phase control is used to minimise unwanted
product effect signals. Fig 3 shows a typical example.
It can be seen from Fig 3 that the phase control
characteristic masks off some of the Stainless Steel
signals and has a minimal effect on the Ferrous
signal. The detectors phase setting may be adjusted
to align the phase control over any unwanted product
effect signal.
PHASE VALUE
0
0
20 0 40 0 60 0 80 0
90
0
100 0 120 0 140 0 160 0
AMPLITUDE
STAINLESS
STEEL
FERROUS
NON-FERROUS
VIBRATION
180
0
VIBRATION
PRODUCT
SIGNAL
Fig 3 Effects of Unwanted Signals
In general if operating the detector with any product
which exhibits a product effect the Non
Ferrous/Stainless Steel sensitivity will decrease.