1. Unlock and remove lid from base of barograph carefully avoiding knocking the arm and pen.
2. Twist the brass arm to bring the nib away from the chart. Remove brass cap from the rotating drum.
3. Remove the central screw from the drum.
4. Lift drum away from the base mount of the barograph.
5. Remove centre slide on drum and carefully take off the used chart; set to one side for storage.
6. Wind your new chart around drum and replace clip. Please note not all barographs have chart clips, some instruments reply on charts being adhered using double sided tape.
7. Replace and attach the barograph drum complete with a new chart for the week.