Temp & flow meter

[mattadler]

I am trying to build I set up where I can measure both temp and and gpm of
water I was if any one has a simple circuit . I am also looking for the trasducers for the same

 

[Marks256]

May i ask how you managed to get three of the same posts? There is what, a 20 second delay before you can post again?

 

[kpsoneji]

I am trying to build I set up where I can measure both temp and and gpm of
water I was if any one has a simple circuit . I am also looking for the trasducers for the same

ya i had studied a transudcer which measure both at same time its thermal flowmeters which includes heat transfer meters and hot wire meters. both uses the characterstics of thermocouple. first of all these transducers indicates the temperature which are then calibrated into flow.

 

[stevez]

Tell us a little more about the application - it will help to reveal a practical solution. A few comments.

Flow: what is the range of flow? 0 (zero) is not a reasonable minimum if you really mean it. What kind of accuracy is required? What pressure drop can you tolerate? What resolution is required? How linear does the signal have to be? Is the water hold, cold, dirty, ultrapure, etc?

The questions related to temperature are much the same.

Again, a description of the application would be helpful.

 

[mattadler]

I have pressure washer that runs at 4gpm at 4000psi around 250f I want to control temp and and know what my outflow is to determin product consumption

 

[stevez]

The pump in many pressure washers are positive displacement pumps and as a result the outflow of the pump is closely connected to the RPM, strokes, etc, as long as the fluid is relatively non-compressible.

Just to back up a bit - take an air compressor with a piston in it that goes up and down. Air is let in then pushed out. The compressibility of air allows for a wide variation in the mass flow rate so it is difficult to relate the strokes per minute to some standard volumetric displacement. Many high pressure water pumps use pistons, like the air compressor. Because water isn't compressible like air, when the piston strokes a fix volume of water is moved. Yes, there is some minor leakage but it's just that - minor.

If this is the case you might monitor motor RPM or pump strokes as a way of determine flow rate. An orifice could be used with a pressure drop method but I don't think the accuracy will be improved over the method I described.