Actually, I think I'm going to concentrate on the Maxim chip for now: it's got a built-in temperature compensator. This means that I'm going for a pressure reading, not a flow reading. I can add flow later, in a permanent installation.
The Maxim chip has a number of DACs built-in for correction, and is programmable, to some extent. The VCO would follow the Maxim chip.
As for the pressure drop measured, if I don't exceed 1.5 gpm, +/- 1 psi would do fine (for heatercores only), but if I later make a permanent installation of it across my pump, even 5 psi won't be enough.
Hum... what to do, what to do...
At +/- 1 psi, the output will spread between 0 and 16.7 mV, which is actually more sensitive than the 50 mV spread (aka "span") on the 5 psi unit.
I could then later adapt this sensor for a flow reading, taking a reading across the HC... and if/when I remove the heatercore, I can add a simple little restriction, to have something to measure.
+/- 1 psi sounds good.
|