What type of scale should I provide?

The measurement scale provided is very important for the accuracy of sensor placement. 

On each floor of the plans provided, we require there to be a measurement scale bar

Alternatively a measurement relative to the plan as below: 

If you cannot locate plans with this scale bar please provide a measurement of a wall or something similar. Ideally, we would like a scale that we can measure 10m/30ft, to minimise scale issues. 

For XY the Scale relates to pixels not print, hence a scale as A3 1:200 is not relevant. 

Where there is no scale provided we can use a door frame, which is usually 90cm. This should only be used as an indicative measurement until a greater accurate measurement can be provided.