Abstract: A fluid flow control valve includes first and second electrically conductive body members separated by an electrically active separation member having electrical resistance. A valve actuation member is slidably located within the second body member, making a sliding electrical contact with the second body member. The valve actuation member can move from a first position spaced from the first body member to a second position electrically connecting the first body member with the second body member, thus forming a low resistance electrical connection. In its first position spaced from the first body member, the resistance of the electrical connection between the body members depends on the electrical resistance of the separation member.