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often resulted in a dangerously mobile demon-powered cart that might at any moment charge the nearest Shadowhunter with unknown intent, clacking madly because of its extreme proximity to its own sensing apparatus. This failed branch of Sensor evolution fell away from the tree entirely in the 1960s when modern rune miniaturization magic made it possible to create Sensors that could be carried in a trouser pocket.
The Shadowhunter interested in its history can find older models displayed in libraries and museum collections of older Institutes.
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Did you Know? No!
    The Codex has a different definition of “interesting” than me
Interestingly, the standard runic labels on the Sensor were originally intended as a temporary measure. In his classic memoir of 1910, A Whoops and a Bang: The Shadowhunter of the Modern Age, Henry Branwell hypothesizes a single Mark that could be used to cause the buttons of a Sensor (or anything else) to appear in the native language of the person holding it. Such a Mark is not known to exist, but Branwell was at that time enthusiastically arguing for the use of warlock magic in collaboration with Nephilim Marks to create new and more complex effects, an unpopular position both then and now (although see the Grimoire, Chapter 6, for a discussion of the history of the Portal). This course of Branwell’s experimentation, however, was disrupted when in 1914 he began a long collaboration with the Iron Sisters, the results of which remain secret to this day. The Mark of Translation remains uncreated, and the Sensor remains covered in runes whose meanings must be committed to memory.
    SENSOR TECHNICAL SUPPORT FREQUENTLY ASKED QUESTIONS
The Sensor is a complex tool, and many Shadowhunters struggle with the nuances of its use. Here we attempt to answer those questions that arise most frequently.
    Yes, that is what “Frequently Asked Questions” means, thank you.
Can the Sensor be modified to detect werewolves, vampires, and other Downworlders?
It cannot. The Sensor is attuned to the presence of demon energy; while Downworlders all have some demonic magic in them, they are not demons and do have normal human souls. Therefore they will not register on a Sensor.
Can the Sensor be modified to detect only certain kinds of demons?
Yes! This is a lesser-known but useful function of the Sensor that requires no modification. The buttons can be manipulated, using the Marks, to isolate only demons who match a certain set of qualities.
Can the Sensor be modified to detect a specific Greater Demon?
No.
Can the Sensor be modified to detect where I left some object?
No.
When will my Sensor support the Flash rune?
The Flash rune referred to here causes a burst of bright holy light, and rumors have existed for years that the Sensor was going to be modified to be able to successfully hold the Flash rune. Unfortunately, the Flash rune currently causes the Sensor’s normal function to slow down and often stop working entirely. As yet, the only Sensors available do not support Flash, and only the Iron Sisters know whether they ever will.
Help, my Sensor’s buttons are all labeled in runes.
Those are Marks.
I haven’t learned these runes yet!
We might recommend a trick long known to Shadowhunters, involving drawing your own labels on the Sensor buttons with a felt-tip marker.
My Sensor is vibrating!
That is within the normal bounds of Sensor operation. When a Sensor is overloaded with the proximity of demon energies, it will begin to vibrate with intensity. This was long considered a deficit in the design of Sensors, but the advent of modern technology has caused many Shadowhunters, especially those more familiar with the mundane world, to regard the vibration as a useful feature.
Unlike the mundane tools that vibrate, the Sensor can become so overloaded with demon energies that it can ignite and explode. Therefore, caution is advised.
My Sensor has vibrated so much that it has ignited and exploded.
You will,