Purpose:  

    JJY-2 Caliper is an instrument specially used to measure the average diameter of well bore. It's four measuring legs closely cling to borehole wall when they are being lifted, as if there are two rules measuring two diameters that are perpendicular to each other. It records depth curve of bore diameter through sensor which changes into electric signal and the signal is sent to the ground instrument by cable. It's widely used in measuring of pore-creating for well drilling and hole filling piles.

The hole diameter curve can be measured as follows:

  1. Determine how much cement is needed when the well is cemented and properly choose the fixed position for annular tube.

  2. Provide necessary information n hole diameter for later well log interpretation and radioactive well log interpretation.

  3. Interpreter collapse of position of a pore well.

  4. Provide information on analysis when quality of pile foundation is examined or measured.

Main technical index:

  1. Scope of measurement: Ф500mm～Ф1200mm ,fixing leg(200mm):Ф1600mm

  2. Measuring  error: ±15mm