Flow Meter Gauge Scale Factor

[b7031719]

I have seen a few differential pressure gauges now with a logarithmic scale in flow units and a scale factor written on the dial e.g. x600 IGPM etc. What is the reason for the x600 scale?

 

[danw2]

It's a square root function, not logarithmic. I suspect that IGPM is imperial Gallons per minute.

The x600 is the scaling factor used with a specific the primary flow element (orifice.venturi) that the gauge is measuring DP across.

Same gauge can be used for 1" line of a 6" line, for the same DP different scaling for the different flow rates in different sized pipes.