This paper describes a capacitive displacement sensor using the spatia
l sampling principle. A first experimental prototype has been manufact
ured. Measurements show that this prototype achieves a resolution of 1
mum and an accuracy of 3 mum over a displacement of 150 mm. The linea
r displacement range can be as large as several metres. The prototype
confirms low sensitivity to both alignment inaccuracies and external i
nfluences like dust and electromagnetic disturbances.