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I've been looking for inexpensive differential pressure transmitters for years, but until just recently, they've all been over $250, which is a bit steep for a single sensor.
I've been hoping that with the advent of returnless fuel systems, some cheap automotive type DP sensors would become available, and it finally looks like there are:
Omega have just come out with this model: http://www.omega.com/ppt/pptsc.asp?ref=PX26&Nav=preb05
With only millivolt type output, some signal conditioning would still be required for it to display on gauges, but at 100mv maximum, it should be sufficient for an ECU to read on say a thermocouple input.
This would be ideal for a boosted application to monitor the "real" fuel pressure at the injectors. With one side referenced to the rail, and the other side to the manifold, you could tell if your fuel pressure was holding steady at high boost, or dropping off - a sign of a fuel pump with not enough grunt, lines too small, fuel filter plugging, etc.
Or if you wanted to get fancy, you could use it with a PWM controller and build your own returnless fuel system.
For the truly serious (or seriously anal) folks, you could put one of these across your oil or air filter to monitor plugging, or your whole intake system to look for excessive pressure drop, or your exhaust to look for excessive pressure drop there too.
Its temperature capability at 80 degrees C is a little low to be monitoring oil, coolant, or exhaust, but I've seen people loop small diameter copper tubing several times before connecting the sensor, and in this way the process fluid is cooled a bit before it hits the sensor.
And if you burn one up, it's not the end of the world - it's only $36!
I've been hoping that with the advent of returnless fuel systems, some cheap automotive type DP sensors would become available, and it finally looks like there are:
Omega have just come out with this model: http://www.omega.com/ppt/pptsc.asp?ref=PX26&Nav=preb05
With only millivolt type output, some signal conditioning would still be required for it to display on gauges, but at 100mv maximum, it should be sufficient for an ECU to read on say a thermocouple input.
This would be ideal for a boosted application to monitor the "real" fuel pressure at the injectors. With one side referenced to the rail, and the other side to the manifold, you could tell if your fuel pressure was holding steady at high boost, or dropping off - a sign of a fuel pump with not enough grunt, lines too small, fuel filter plugging, etc.
Or if you wanted to get fancy, you could use it with a PWM controller and build your own returnless fuel system.
For the truly serious (or seriously anal) folks, you could put one of these across your oil or air filter to monitor plugging, or your whole intake system to look for excessive pressure drop, or your exhaust to look for excessive pressure drop there too.
Its temperature capability at 80 degrees C is a little low to be monitoring oil, coolant, or exhaust, but I've seen people loop small diameter copper tubing several times before connecting the sensor, and in this way the process fluid is cooled a bit before it hits the sensor.
And if you burn one up, it's not the end of the world - it's only $36!
