The plug has come off the turbidity sensor, but it will go on either way. Can anyone tell me which way it should be fitted? The wires are colour coded and the PCB is numbered.

William, December 2010

Thanks ck. I suspect it is polarity sensative as the sensor consists of a transmitter and a receiver I.R Led, there are 3 wires on the plug One is common to both the transmitter and receiver and of the other Two One goes to the transmitter led and the other the receiver. But thanks for the suggestion anyway.

William, December 2010

usually if they are not keyed/polarised they are not polarity sensitive so can go either way without any effect

ck, December 2010