Poi-Savant

Spending time in xenos environments means that sooner or later one will have to sample the “local” cuisine, which may not resemble anything one is used to. Indeed, some travellers try to opt for a plant or creature that has a “familiar” appearance, but this is no less dangerous—for the assumption that a given thing must be safe to eat based on resemblance is a foolhardy one. Enter the poi-savant. A hand-held cogitation device, the poi-savant measures various levels of bio-chemicals and searches for signs of a diverse number of dangerous toxins in any substance that it is used to analyse. Any substance the poi-savant clears as “edible” is safe for human consumption, though not necessarily appetizing.

Originally developed on Malfi, where the noble houses even now use them at every meal, poi-savants tend to be remarkably accurate devices as they have had well over a thousand years of field-testing. Indeed, many Malfian nobles make a point of commissioning their own personally tailored poi-savant, generally by miniaturizing them into elegant wands or ornate rings that they can simply pass over their meals without appearing unduly concerned (or rude). Personal poi-savants must be updated regularly as new toxins are identified, leading to an ongoing race between their cogitators and the cunning of the countless assassins who constantly seek out new poisons in the hope that they will thwart their target’s poi-savant.

Source

 * Dark Heresy: Inquisitor's Handbook (RPG), pg. 153