MP3V5050GP – ported pressure sensor

mpv3v5050gp_pic

The MP3V5050GP is an integrated Silicon Pressure Sensor, On-Chip Signal Conditioned, Temperature Compensated and Calibrated.

You can use this sensor to monitor the water level in a container. It’s range is from 0 to 50 kPa. The equivalent height of a  column of water is around 17 feet !! . You can use this sensor to monitor the water level in one of those big PVC tanks on the terrace if you are lucky enough to have one. Note that this device is a gauge type pressure sensor. Such sensors measure pressure with respect to atmospheric pressure.  The output of the sensor is proportional only to the pressure of the water column inside the tank.

This sensor has a barbed port which can be fitted with a tube. The other end of the tube should lie  at the bottom of the tank. This can be done by attaching a small weight to the open end of the tube. The weight is necessary since the tube has a tendency to float. The sensor can thus be attached to the outside of the tank with only the tube exposed to water. Note that the sensor does not and should not come in contact with water even through the pressure port. When the tube (with one end attached to the sensor’s port) is immersed in water, air gets trapped inside the tube. The pressure of the water compresses this air.  This compressed air transmits the water pressure to the sensor.

We have imported 100 feet of Tygon lab tubing from Cole Palmer. This tube’s inner dia is 3/32 inches and outer dia is 5/32 inches. It is a perfect fit for the MP3V5050GP. Once we attached the tube to the sensor, we could not detach it.  We tested the the output of the sensor with a voltmeter. As expected, the output tracked the water level in a bucket.

We now have a easy way to monitor the water level in a tank. Attach this sensor to a solar powered WiSense node and get water level alerts on your phone.

mp3v5050gp_tank_level

Power consumption is an issue. According to the spec, it’s current consumption is max 10 milli-amps which is not insignificant if battery powered. The sensor does not have a low power / shut down mode. It is always sensing. One way is to use a load switch to turn off power to the sensor.  The load switch can be controlled through a GPIO pin.

This sensor is not cheap. Digikey is selling it at $10 if you buy 10. The cost drops to $ 6.0 if you buy 100.

Details

  • Manufacturer: Freescale
  • Part Number: MP3V5050GP
  • Package: 8 Lead SOT  (Surface-mount Device)
  • Pins: Vcc, Gnd and Vout
  • Interface: Analog voltage
  • Range:  0 kPa to 50 kPa
  • Accuracy: +/-  2.5 % VFSS
  • Power supply: 2.7 Volts to 3.3 Volts
  • Current consumption:  10 milli-amperes max
  • Data sheet: http://www.freescale.com/files/sensors/doc/data_sheet/MP3V5050.pdf

Posted on December 2, 2013, in Uncategorized. Bookmark the permalink. Leave a comment.

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