HPT用于測試地下土壤的水力穿透性。當該工具以固定速率鉆進入地下時，將固定壓力水通過探頭側的濾網注射入土壤。壓力傳感器測量水注入土壤時的反應壓力。該反應壓力與土壤傳導水的能力有關。壓力和水流量以及深度都被記錄，從而得出土壤的滲透性。

What is Geoprobe^® Direct Image^® HPT?

• HPT produces a detailed log of relative bation permeability
• Can be used to estimate hydraulic conductivity in the saturated zone
• Logs HPT injection pressure, flow rate and electrical conductivity
• Use pressure dissipation tests to measure hydrostatic pressure
• Determine piezometric profile and water table depth
• Can be used to map salt and brine contaminant plumes
• HPT logging is easy to learn and operate
• Interpretation of HPT logs is straight forward and intuitive

The Hydraulic Profiling Tool is a logging tool that measures the pressure required to inject a flow of water into the soil as the probe is advanced into the subsurface.  This injection pressure log is an excellent indicator of bation permeability.  In addition to measurement of injection pressure, the HPT can also be used to measure hydrostatic pressure under the zero flow condition.  This allows the development of an absolute piezometric pressure profile for the log and prediction of the b of the water table.  The piezometric profile can be used to calculate the corrected HPT pressure.  This data along with the flow rate can then be used to calculate an estimate of hydraulic conductivity (K) in the saturated bation.