Divergence Meter

The Divergence Meter is a device brought back from 2036 by Suzuha, invented by the future Okabe for his own personal use.

It is an array of Nixie tubes that uses an unknown method to determine the "Divergence Value" of the current world line in relation to the absolute world line of 0%.

The Divergence Meter is used to calculate what Attractor Field the universe is currently in. Throughout much of the storyline, Okabe tries to break the 1% barrier (create a world timeline change so significant as to raise the first, leftmost Nixie tube value from a 0 to a 1) to escape from the Alpha range, using the meter as a reference each time.

Okabe is the only one who can effectively use the meter, as his Reading Steiner allows him to remember what its previous values were across world line changes. To anyone else, the numbers always follow the same pattern inside his or her corresponding world line.

Even Suzuha, who herself had time-traveled to bring the future device to present-time Okabe, couldn't tell if it had changed. According to Tennouji's recollections of her  near the end of episode 16:  in her final year of life, she was always wondering  if she was able to successfully alter its values because of her actions:


 * Suzu-san had this. Do you know what the number means? She was always looking at it, from her hospital bed. "Is this the number before it changes or after? Did I manage to change it?" Whatever it was, it bothered her to the end. — Yuugo Tennouji

In the future time of its first invention, it was originally in Okabe's possession; when he died, it was passed on to Daru, and in turn was passed on to Suzuha. Suzuha then traveled back in time to give it to Okabe, completing the cycle and having the Divergence Meter's existence contribute to its own invention without realizing it.

It has some limitations in that it cannot display certain values; this is shown in the Omega Attractor Field, in which the first digit cannot be displayed due to the divergence being negative.

Heliopause Processor (Final Phase)
Spoilers for Robotics;Notes DaSH''' As of 2020, Okabe resides in the United States and researches at Viktor Chondria University alongside Kurisu and Maho Hiyajo. Hashida mentions that after Okabe came up with the "Worldline Theory", he changed significantly and migrated to study with known geniuses. During that time, Okabe reinvented his Divergence Meter to watch over the Worldline; however what it has revealed recently shows that The Steins Gate is in jeopardy. The meter will display 1.048596 as it should, but occasionally twitches, changes numbers, or glitches. This worried him enough to contact Hashida, by which Hashida mentions Okabe never goes out of his way to make calls or message. He relayed one message to Hashida before calling him: "The Worldline is wavering..."

Trivia

 * Final Phase starts by showing two numbers simultaneously visible: 1.048596 and 1.123581