The new T1/T2 level sensors (Omega LVCN414) were hooked up to the PLC and the test performed on June 11 was repeated.

The water level above the base of the bucket was measured using a tape measure, as well as with the level sensor at various intervals as the bucket was filled and then drained:

Tape Measure Level (cm) --- Reading from Ultrasonic Level Sensor (cm)

Empty --- 0
3.3 --- 3.3
6.7 --- 6.7
12.2 --- 12.2
20.5 --- 20.3
29.2 --- 28.5
36.6 --- 36.3  (Last measurement on June 17, left overnight, see graph below)
36.6 --- 35.6 (First measurement on June 18)
31.3 --- 30.2
22.0 --- 21.9
13.1 --- 12.3
7.3 --- 6.5
Empty --- 0

Data was recorded while the sensor was left overnight (see attached plot).  After approximately 2 hours, the sensor stabilized and then fluctuated less than 0.1cm for the next 12 hours.  Overall these tests proved that this sensor will be suitable for the intended application and the parameters used for configuration are appropriate.