Henry_Best:
Chagrin:
I'm not sure a "balloon" type system would work quite as expected. When weight is added to the hive the balloon will flatten out and result in a non-linear pressure reading at your manometer?Using the example of a car tire, pressure measured in PSI, the footprint (in square inches) of the tire multiplied by the inflation pressure equals the weight supported by the tire (an "ideal" tire, ignoring sidewall stiffness, etc.). When weight is added the footprint can increase and the pressure can stay near or at the original pressure.
I might be totally off my rocker.
Not off your rocker, but have you thought about a flat square 'balloon', the same size as the base of the hive? Remembering that he's starting with 100+ Kgs on it, the few grams more or less wouldn't make any difference at all to the footprint.
But after sleeping on the idea, I realised that a manometer system would need an equal weight of oil to balance the hive. 200 litres of hydraulic oil doesn't come cheap!
Or you could measure the height of the flattened balloon... I would use an inner tube to rest something on and maybe fill with dry CO2 or nitrogen.
But I think that his load cells are better than springs of any type.
I understand that putting mechanical strain on any conductor changes its resistance, even copper.