According to the 1964 edition of The Roman Ritual (The Bruce Publishing Co.), the following prayer/ceremony, to be conducted by a priest with the assistance of one or more other people, is a valid way of blessing a seismograph machine. This prayer was approved by the Congregation of Sacred Rites on Feb. 13, 1924.
Priest: Our help is in the name of the Lord.
Response: Who made heaven and earth.
Priest: The Lord be with you.
Response: May He also be with you.
Priest: Let us pray.
Priest: Almighty everlasting God, whose very gaze causes the Earth to tremble, pour out your blessing on this seismograph; and grant
that the signs of the Earth's tremors may be precisely recorded by it, and then rightly interpreted by man, both for the benefit of your people and for the greater glory of your name; through Christ our Lord.
Priest: O Virgin Mary, in view of your own sorrows take pity on us and pray for us.
St. Emidius, pray for us, and in the name of Jesus Christ of Nazareth, protect us and also this seismograph from the terror of
The priest then sprinkles the seismograph with holy water.
After having consulted with an author/former priest-in-training, I believe the above noncommercial, educational duplication of the prayer to be a fair use, since prayers are intended for free public performance during religious ceremonies.