Technical reports: Liquid presence sensing

Chemical Detection

At LAIIER we have carried out a series of tests for our Severn sensors to show their performance for a range of liquids and setups. Here we present a technical report for the Severn sensor when in contact with different chemicals.

Isopropyl alcohol (IPA)

Measuring the response of the Severn sensor to anhydrous IPA. As IPA is a polar solvent, we expect some conductivity.

Procedure

Set up for measuring the response IPA on the Severn sensor

99.9% pure, anhydrous IPA solution was used for this experiment. Approximately 1 ml of the IPA was dispensed from a micropipette onto the Severn sensor at a fixed height.

The Severn sensor was connected to the Severn board in order for serial data to be collected. The IPA was dispensed at 10 seconds.

Results and findings

  • The graph shows a clear change in sensor reading when the IPA is dispensed.
  • Reading further decreases signifying that the IPA is becoming more conductive as it is left in contact with the surrounding air.
Graph showing chemical detection on the Severn sensor

Conclusion

In summary, the Severn sensor can easily detect as little as 1 ml of IPA solution.