I've been down the local wholesalers tonight and wanted to buy a small light with a sensor/pir built in. Nothing spectacular, so he starts talking about a High Frequency Sensor Module to put in a Knightsbridge opal bulkhead, it uses microwaves. It was late In the day so I agreed to take it. Now luckily I'm not busy tonight so I thought I would try and see how it all goes together. I read the instructions and get to the first section, it says "High frequency signal is able to penetrate non-metallic materials such as wood, brick, glass, etc but it can not penetrate water or metal" The bulkhead tray is metal. Then it says in section 2 Helpful Tips for Installation... "DO NOT install the sensor module in a closed space made of metal." I've not used one of these before so I have no clue...
