Range is from 10-50 Pounds Elevator Door Pressure Gauge instrument instrument specifically designed to measure the higher forces typically encountered with elevator doors. Door Pressure Gauge MEET ADA REQUIREMENTS. OPERATING INSTRUCTIONS Set the top (small) o-ring located on the plunger rod on zero, down against the instrument's flange; or set the o-ring on the desired force. Holding the instrument firmly, press slowly against the door at a point approximately handle-high, and 30 inches away from the door's hinges. Read the amount of force required to open the door on the plunger scale closest to the bottom of the small o-ring.