Abstract: A portable panel position detector for determining the orientation of panels being serially moved on a transfer line into a downstream panel treatment facility comprising a pair of support towers laterally spaced to allow the passage of line supported panels therethrough. The spaced support towers operatively mount elongated and vertically extending sensor strips in opposing spaced relationship that defines clearance-determining gating between the towers. In the event a panel moving through the restricted gate is not properly orientated on the transfer line, at least one sensor strip or a portion thereof will be deflected by physical contact with the panel moving therethrough. The displaced strip effects the triggering of an alarm that advises a transfer line attendant that the panel is improperly loaded. The panel can be appropriately repositioned on the transfer line so that it can successfully pass through the treatment facility without damage.