Converting Span to Percentage / Another Span

General
1

Hi All,

I dont know how to phrase this, and I am not feeling well today, so my brain is working at half speed.

Anyway, I have a SR04 Ultrasonic Distance Sensor feeding into Nodered (via Tasmota) for a Water Tank.

When the tank is full, the distance to sensor is 19cm, when the tank is empty, the distance to sensor is 150cm.

I need a way to convert the span of 19cm->150cm into 100% to 0% or similar, so that it is more humanly readable.

Is there an easy way to do this. I would probably figure it out if I was firing on all 4 cylinders today.

Thanks

2

Nevermind.
Found the 'Range' Node. That looks like it is what I was looking for,

Peter

3

Indeed it is... should be fine for simple cases... If your tank is some other shape (tapered for example) then Bart's tank volume node may be better

4

Thanks.
The tanks are cylindrical, so it is easy enough to do that span using that Range Node.

Peter