Technical description

4 – 20 mA

CAN/RS-485 Modbus

Power 24 VD

Low energy, high frequency radar pulses are generated by

the Signal Processing Unit (SPU) and transmitted via coaxial

cables to the Stationary Antennas installed inside each cylin

der compartment.

The antenna transmits the signal further into the open space

of the crankcase. When the sensor passes the antenna,

the radar pulse is picked up. The SAW element at the tip of

the sensor then reflects the signal which is picked up by the

stationary antenna and sent back to the processing unit for

interrogation.

The shape and characteristics of the reflected pulse deter

mine the temperature of the sensor, i.e. the bearing temper

ature. The processing unit software calculates the tempera

ture and transmits this to the engine control and monitoring

system.

The SPU uses a multiplexer to monitor up to 16 channels in

sequence. Calculation time for each channel is appr. 25 ms.

Installed on a 10 cylinder engine running at 600 rpm all 10

channels are up-dated in less than one second.

The multiplexing and low signal strength reduces noise and re

moves any danger of overhearing from one cylinder to another.

All sensors and antennas can therefore be similar. This reduces

number of variants and represents a huge benefit in terms of

keeping spares.

Mechanical design and installation