When vigorous temperature fluctuations affect sensor readings, using a Reference Target can improve ultrasonic accuracy. Delrin adapter works with 30mm or 1” NPT ToughSonic 3 and 14 sensors, adapter fits 2” NPT tank mount.
More on the ToughSonic Reference Target
UA-RT1-1NPT ~ Reference Target Adapter with target for 1 in. NPT thread
UA-RT1-30MM ~ Reference Target Adapter with target for 30mm thread