Additel ADT155 [ADT155-02-DP800] Internal Pressure Module, ±0.02%FS Accuracy, -380 to 800 inH2O (-13.5 to 30 psi) Pressure Range - Differential. The Additel ADT155 Pressure Module for ADT760 calibrators improves the consistency of your devices. It slots into automatic pressure calibrators to adjust the range and reliability of the results. The module can be replaced with similar upgrades to customize the readings for a specific operation.