Security Light Leaves Sensor in the Dark

Richard Hyde-Moxon bought this nifty-looking security light from Homebase.

The light has three adjustable settings for “ON duration,” “Low level brightness,” and “ambient light,” at which the light is activated. Inexplicably, the control panel is located just above the passive infrared sensor:

The panel is accessed by sliding a cover forward over the sensor:

The instructions tell you that to adjust the ambient lighting condition for which you want the light to come on to wait until the time of day at which that light level is achieved, then adjust the screw pot until the light comes on.

The only problem, of course, is that when you slide the cover down to access the pot, the sensor is covered. The sensor thinks that it’s dark, and the light comes on!! Adjusting the sensor can only be achieved by trial and error over a few nights, which kind of defeats the whole purpose.