Week 2: Flow Meter Testing

Test 1: Determine Accuracy of Sensor Flowrate Measurements

To determine whether the flowrate is sufficiently accurate to measure the instantaneous flowrate, its measurements was compared to experimentally derived flowrates.

To connect the flowmeter to 3/8" vinyl pipelines, two reducing connectors was used. To prevent leaking, sealant tape was used to close openings within the flowmeter's threads and hose clamps was used to connect the pipes to the reducing connector. The flowmeter connections can be seen in Figure 1.

Figure 1: Flowmeter Setup

To grab the sensor measurements, an Arduino Code Sample was used, which uses an interrupt pin to read the pulse frequency as sent by the flow meter. For more details, please visit "___________________"

Figure 2: Arduino Code Sample

Test 1 Required Components:

1. Flowmeter (insert part number here)

2. Pump (insert part number here)

3. DC power supply

4. 3/8" vinyl tubing

5. Hosing Clamps

6. Sealant Tape

7. Reducing Connectors

Test 1 Procedure:

1. Fill a reservoir with 750mL of water

2. Connect the pump 5V and GND lines to DC supply's +ve and -ve lines (CH1)

3. Adjust the output voltage to 12VDC and output current to 2A

4. Connect the flowmeter's 5V and GND lines to an Arduino Uno's 5V and GND lines, respectively. Connect the flowmeter's signal pin to an Arduino Uno's IO pin, as specified in the associated code

5. Turn on the DC power supply and the Arduino Uno. Measure the time it takes to displace the 750mL from its reservoir to another, and calculate the flowrate using the known volume and measured time. Compare this value to the flowrate measurement from the Arduino

Test 1 Results:

Calculated Flowrate: 52mL/s -> 3.12L/min

Flowmeter Flowrate: 57mL/s -> 3.42L/min

Flowmeter Error: 8.77%

Observations:

• Flowmeter flowrate values are reasonably accurate (8.77% error), but requires further testing and improvement to reduce errors.

• Flowrate discrepancies hypothesized to be caused by delay ( period in time where no fluid was passing through flowmeter, since system started out with no water traversing the pipes)

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