gravity induction

[thomaspfenning]

This may be one for Dave Jones.  I bought a water filter from amazon.  It has a water quality sensor built in ( they claim) ,  You push the button and a blue led comes on, and supposedly when the filter needs changing the red light comes on.  Mine started blinking blue.  This appears to be a fault the company claims and needs to have the gravity induction sensor replaced. I got curious.  The only other reference to a GIS (gravity induction sensor) is with a coffee cup heater which just turns on a heater due to the weight of the coffee mug (gravity).  So, I took the unit apart.  I found a 8 pin microcontroller and a 2 pin smd device acting as a voltage divider with the battery feeding an input of the MCU. Plus the 2 led's.  The smd device is odd, it has gold plated ends with a grey plastic center, unlike any device I have seen so far.   The only other clue as to what this is doing is the printing on the small pcb saying "three month".  So is this just a timer device to make you buy a new filter every three months. Then why use  the strange sensor device.  And how would the device know when the filter was used.  My thought is that maybe the device is a tilt sensor and it counts usage by the number times it gets tilted. I will test the device for that action.
If anybody knows what this is or why nowhere on the net is there any explanation, especially by the company which can by found by searching for gravity induction.

[TimFox]

Back in grad school,  we used legitimate water filters to produce de-ionized water for laboratory purposes.  The simple indicator for cartridge replacement measured water conductivity by putting noble electrodes in the water, which would short out a neon bulb when the conductivity was too high.