Fiber writing pen for thermo-hygrographs

Change of felt-tip pens

Typically, felt-tip pens work flawlessly for about a year. If the recording becomes too weak, replace the corresponding fiber pen. To do this, disengage the writing arms, with the right hand raise the writing arm approx. 2-3 cm and with the other hand pull the felt-tip pen to the left. Slide on new felt-tip pen as far as possible and remove protective cap. Slowly lower the writing arm and let it go. After the change both felt-tip pens must write on the same time line. If necessary, postpone a tip a little less.