A humidity detection sensor includes a lower electrode provided on a board, an upper electrode provided so as to face the lower electrode, a humidity sensing film which is formed at least between the lower electrode and the upper electrode and whose dielectric constant changes in response to humidity, and a protective film provided so as to cover the upper electrode. The display window and the auxiliary plate are oriented at an angle of tilt 1, preferably substantially vertically, the volume in between the display window and auxiliary plate is filed up to a selected level height with uncured resin, a seal and an opening being provided at or near the highest point. At the ends of the cross member, two seats mounted; the seats may optionally be positioned to face directly backward or be angled inward to face one another. The tracking loop comprises a reference code generator and an interpolator for generating timed signal versions in response to said communication. The baby carriage is therefore able to move.