A device for indicating differential pressure between two spaces , the device permitting fluidic pressure connection of a first space and a second space separated by a barrier, the device comprising: a first conduit configured to be in fluid pressure communication with the first space when the device is installed in a barrier separating the first space and the second space ; a second conduit having an opening that can permit fluid pressure communication between the second conduit and the second space when the device is installed in the barrier, wherein the second conduit is in fluid communication with the first conduit , and an angle of inclination of the second conduit is adjustable with respect to a horizontal reference plane such that a first region of the second conduit is vertically lower than a second, vertically higher region of the second conduit, and the angle of inclination of the second conduit is adjustable independently from an angle of inclination of the first conduit ; and at least one movable element movable within the second conduit from the first, vertically lower region to the second, vertically higher region in response to a differential fluid pressure between the first and second spaces ; wherein the second conduit comprises a pivot arm that is rotatable about a pivot axis , characterized in that said second conduit is parallel to a first side of the barrier, and is adjustable within a vertical plane; the device further comprises a transition region where a passageway is first surrounded by the pivot arm when traveling in a direction toward the pivot arm ; and the pivot arm is arranged such that pivoting the pivot arm within the vertical plane does not change a location of the transition region relative to the first conduit . a first conduit configured to be in fluid pressure communication with the first space when the device is installed in a barrier separating the first space and the second space ; a second conduit having an opening that can permit fluid pressure communication between the second conduit and the second space when the device is installed in the barrier, wherein the second conduit is in fluid communication with the first conduit , and an angle of inclination of the second conduit is adjustable with respect to a horizontal reference plane such that a first region of the second conduit is vertically lower than a second, vertically higher region of the second conduit, and the angle of inclination of the second conduit is adjustable independently from an angle of inclination of the first conduit ; and at least one movable element movable within the second conduit from the first, vertically lower region to the second, vertically higher region in response to a differential fluid pressure between the first and second spaces ; wherein the second conduit comprises a pivot arm that is rotatable about a pivot axis , characterized in that said second conduit is parallel to a first side of the barrier, and is adjustable within a vertical plane; the device further comprises a transition region where a passageway is first surrounded by the pivot arm when traveling in a direction toward the pivot arm ; and the pivot arm is arranged such that pivoting the pivot arm within the vertical plane does not change a location of the transition region relative to the first conduit . <EOS>