Re: Weighing machine
I was advised to weigh every day when I was diagnosed with heart failure.
This was to check if I was retaining fluid, and a sudden increase in weight was much more important (and life threatening) than my actual weight.
My weight has always fluctuated for as long as I can remember by 1 -1.5kg on a day to day basis, so an increasing trend is a better indication of fluid retention for me than a single increase in weight.
As far as weighing devices are concerned, their readings always drift. They should be recalibrated on a regular basis, but domestic products never are.
It doesn't matter whether they are scales, thermometers, or tyre pressure gauges, they all change over time, irrespective of whether they are electronic or mechanical devices.
Scales in particular need a fixed stable base upon which to sit. A hard solid floor is best. Hollow floors such as floorboards with a covering are the worst.
They also need consistency. Moving scales even by a small amount will give a different reading.
That may not of course be the reason here. However, if one person's weight has increased but not the other, then it would suggest that person's weight has indeed increased.
If both person's weight has increased by roughly the same amount, then it would suggest there is a problem with the weighing machine.