In this article, we’ll outline the setup of an experimental application in which we use a pressure transmitter to measure the amount of pressure that’s being exerted by a column of water in a water bottle, and from that measurement, the pressure transducer can automatically calculate the water column’s height.

We’ll be measuring hydrostatic pressure with a fixed volume. This measurement is unaffected by surface area of the water column; it depends solely on its height.

Materials:

For this application, we use the PX3005 differential pressure transmitter to measure the height of the water column in bottle. Results will be given in inches.

Besides the water bottle and pressure transmitter or a pressure transducer, the experimental setup requires a few additional accessories. These include a 1/4-inch PT adapter and a latex pipe to connect the pressure transmitter’s port to the bottom of the water bottle. Because the PX3005 has an M12 connection, we also need an M12 cable assembly. To power the pressure transmitter, we use a 24-volt DC power supply.

Procedure:

  1. Begin by connecting the PX3005 to the power supply using the cable assembly. Once connected, the unit will turn on.
  2. Next, connect the latex tube directly to the high side of the the PX3005. Leave the low side open to the atmosphere.
  3. To specify the units in which you’ll be reading the pressure exerted by water column, follow these steps. Press the middle “M” button until you see “U” followed by a unit of pressure on the display. This might be “U PSI” or “U bar,” depending upon the unit’s initial setup.

    Once you see “U PSI,” press the “Z” button. Once the “Z” button has been pressed, the display should show “set.” Now press the “S” button, and the device should show you a list of available units that you can scroll through. In this case, we want the reading to be in inches of water column, so stop at “INH20.” Press the “M” button once to save this setting. The unit should display a “U” followed by “INH20” and five bars. Now keep pressing the “M” button all the way until you see a reading of six, which is 00 offset. This indicates that no pressure is being applied. The pressure units should now be displayed in INH20.
  4. To confirm the offset, which should always be zero when no pressure is being applied, hold down the “S” and “Z” buttons at the same time for five seconds. The display should show “PV=0.” Then the unit should return to run mode.
  5. The next step is to fill the water bottle. We will be able to verify the pressure transmitter’s result by measuring the column of water with a ruler and comparing the two numbers. In this case, the ruler shows a water column height of about 6.4 or 6.5 inches.
  6. Read the water column height measurement on the pressure transmitter’s display. For this experiment, it’s 6.623, since the water bottle’s shape isn’t perfectly uniform. Though not completely accurate, this result is close enough to show that our experimental setup can be used to measure the height of a water column.

With a uniform container, the PX3005 can be used to measure the height of a water column in many other applications.

 

If you have additional questions how to pressure transducers or pressure transmitters in applications, contact us today. A member of our team will be happy to help.