it's just a sign, there is no magic detector. singapore is a very dense city and all the buildings are tall, if such a thing existed there would have to be a whole industry to support installing these sensors into all the elevators in singapore. they would be a commercial product. so, where are they? i searched for 'elevator urine detector' and no such product exists. unless you contend there is a top secret government lab in singapore where they make these for the special singaporean elevator safety unit?
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