Technical reports: Liquid presence sensing

Food Item 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 food items.

Food items

Measuring the response of the Severn sensor to a range of food items to determine what could be detected. The food items included:

  • Tomato sauce
  • Malt vinegar
  • Semi-skimmed milk
  • Mayonnaise
  • Sugar solution (60% sugar dissolved in tap water)
  • Honey

Water-based and acidic items were predicted to be more detectable than sugar-based liquids.


Set up for measuring the response of food items on the Severn sensor

A micropipette was used to dispense around 0.04 ml of each liquid onto the Severn sensor and volumes were increased until detection.

The Severn sensor was connected to the Severn board in order for serial data to be collected. All liquids were dispensed at ten seconds.

Results and findings

  • All items apart from the honey could be detected at 0.04 ml. Honey produced a significant sensor reading drop at 1 ml.
  • As predicted, the sugar-based items (honey and sugar solution) had a smaller change in reading as compared to the water-based foods.
Graph showing food item detection on the Severn sensor


All tested food items could be detected with at least 1 ml on the Severn sensor. The sensor can distinguish between water-based, acidic and sugar-based food items where the sensor is most sensitive to water-based foods.