SKF MTx, Техническое руководство, Страница: 20 / 68

HARDWARE MTx
1 - 6 - 18 SKF Condition Monitoring Centre – Steyr
There is a possibility to connect other sensors with a voltage-output less than the 24V.
Thereto the gain of the input-amplifier is adjustable. By using the amplifier there is a pos-
sibility to get better resolution on the ADC.
For example:
Your sensor delivers only 0 V to 10 V the ADC will be used in a range of
so 0 V to 1,28V. If the amplifier with a gain of two (adjustable in the software) is used there
are 0 V to 2,56 V at the ADC and so a better resolution in the digital-converted results.
But be aware, if the input exceeds the 3,3 V the ADC will stuck at his maximum and maybe
information will be lost without any error.
Parameters in software
1. Name:
Description of the voltage sensor
2. Unit:
Unit description of the sensor
3. Sensitivity:
Defines the sensitivity of the used sensor in mV/measured unit.
4. Offset:
Defines the offset of the sensor in the measured unit
5. Gain:
Defines pre-amplification as described in the text above.
Voltage input
Input ............ Umax = 24 V
Sensor ......... maximum signal voltage USignalmax [V]
Gain depends on calculated x:
Examples
USignalmax = 10 V -> chosen gain: 2
USignalmax = 7 V -> chosen gain: 2
USignalmax = 3 V -> chosen gain: 5
Gain
1 < x < 2 1
2 < x < 4 2
4 < x < 5 4
5 < x 5
10 V
7 8

----------
1 28 V

=
x
Umax
USignalmax
-------------------------------- =
x
24
10
------ 2 4

= =
x
24
7
------ 3 4

= =
x
24
3
------ 8 = =