Turbine Rotation Speed; Microphone - SAMES KREMLIN PPH 308 User Manual

3.3.2. Turbine Rotation Speed

Measurement of rotation speed is based on an acoustic principle.
Air enters via the injector holder. The machined groove in the "microphone reader" on the bell
cup allows rotational air through.
This pressure variation generates a noise, or "frequency signal", which travels through the
injector holder and is picked up by a microphone.
The microphone converts the acoustic signal into an electrical frequency signal in order to be
processed by the turbine speed regulation module. One pulse is emitted for each revolution.
Microphone input
Required pressure
1.9 - 3 bar

3.3.3. Microphone

see RT Nr 6190
The microphone is linked to a SAMES KREMLIN frequency/voltage control to convert the
analogue frequency signal into an analogue level signal (0 - 10 V) or digital signal (pulse).
Please contact SAMES KREMLIN for the appropriate part number for use with your set-up.
Index revision : C - November 2017
Required minimum length
4.5 m
23
Outer dia.
1/4"
Maximum length
8 m
7030