Speed limit repeater signs

[t140v]

I have recently been photographed by a mobile speed camera (an UltraLyte 1000).
The road in question has signs on the edge of the carriage way which are a red disc, white background and the number 30 with text underneath "SPEED CHECK"


Repeater signs are prohibited where there is an adequate system of lighting and the default speed limit of 30mph applies. (direction 11(4)) which would mean that I could not be prosecuted if this is a repeater sign.

Does anyone know if this is a repeater sign or just an information sign about speed checks?


Any help would be appreciated.

Thanks