The present invention provides a measuring device, which comprises a leveling unit, a measuring device main body provided on the leveling unit, a control unit, a first tilt angle measuring device for detecting a horizontality with high accuracy, and a second tilt angle measuring device for detecting a tilt angle in a wider range than a range of the first tilt angle measuring device and having a higher responsiveness than a responsiveness of the first tilt angle measuring device, wherein the control unit, the first tilt angle measuring device and the second tilt angle measuring device are provided in the measuring device main body and wherein the control unit drives the leveling unit based on a detection result of the second tilt angle measuring device, performs a rough leveling until a tilt angle detected by the second tilt angle measuring device reaches within a range in which the first tilt angle measuring device is capable of detecting and levels the measuring device main body horizontally based on a detection result of the first tilt angle measuring device.

The invention provides a tilt angle measuring device, which comprises a discoid container for including a liquid forming a free liquid surface, a light emitting source for allowing a detection light to enter the free liquid surface, a photodetector for receiving the detection light reflected on the free liquid surface and a signal processing unit for detecting a tilt of the free liquid surface based on a detection signal from the photodetector, wherein the signal processing unit sets a detection light storage time of the photodetector so that an error incidence rate of the detection signal is a predetermined value.

The invention provides a tilt angle measuring device, which comprises a discoid container for including a liquid forming a free liquid surface, a light emitting source for allowing a detection light to enter the free liquid surface, a photodetector for receiving the detection light reflected on the free liquid surface and a signal processing unit for detecting a tilt of the free liquid surface based on a detection signal from the photodetector, wherein the signal processing unit sets a detection light storage time of the photodetector so that an error incidence rate of the detection signal is a predetermined value.

A method for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates. An annular coplanar capacitance measuring head of a sensor unit consists of four quarter round metal plates and four quarter circular-ring-shaped metal plates, the eight metal plates are coplanar and concentric with one another, and a quarter round metal plate and a quarter circular-ring-shaped metal plate corresponding to the same sector angle form a capacitor. Two annular coplanar capacitance measuring heads are arranged on two round insulating substrates, the two round insulating substrates are used as two bottom surfaces of a cylindrical container, the cylindrical container is transversely arranged, and an insulating liquid equal to volume of the cylindrical container is injected into the cylindrical container in a sealing manner. Potential leads extract potentials of the sixteen metal plates and are connected to an input end of a capacitance measuring unit, and the capacitance measuring unit is connected to a dip measuring unit. When the cylindrical container tilts, the relative positions of the two annular coplanar capacitance measuring heads and the insulating liquid are changed, and a dip angle value can be calculated by measuring the change of a capacitance value. Also disclosed is a device for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates.

A method for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates. An annular coplanar capacitance measuring head of a sensor unit consists of four quarter round metal plates and four quarter circular-ring-shaped metal plates, the eight metal plates are coplanar and concentric with one another, and a quarter round metal plate and a quarter circular-ring-shaped metal plate corresponding to the same sector angle form a capacitor. Two annular coplanar capacitance measuring heads are arranged on two round insulating substrates, the two round insulating substrates are used as two bottom surfaces of a cylindrical container, the cylindrical container is transversely arranged, and an insulating liquid equal to volume of the cylindrical container is injected into the cylindrical container in a sealing manner. Potential leads extract potentials of the sixteen metal plates and are connected to an input end of a capacitance measuring unit, and the capacitance measuring unit is connected to a dip measuring unit. When the cylindrical container tilts, the relative positions of the two annular coplanar capacitance measuring heads and the insulating liquid are changed, and a dip angle value can be calculated by measuring the change of a capacitance value. Also disclosed is a device for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates.

An electrolyte solution for corrosion and meniscus inhibition within an electrolytic tilt sensor by use of functional materials. These functional materials are used in an electrolyte solution having at least one of a rare earth metal salt, anionic surfactant, and a hydrotrope. Additionally, the same electrolyte solution can include a non-ionic surfactant.

An electrolyte solution for corrosion and meniscus inhibition within an electrolytic tilt sensor by use of functional materials. These functional materials are used in an electrolyte solution having at least one of a rare earth metal salt, anionic surfactant, and a hydrotrope. Additionally, the same electrolyte solution can include a non-ionic surfactant.

In the embodiments herein, an instrument for level and plumb determinations, includes: a sealed chamber of equal dimensions made from transparent or translucent material marked with center lines and filled with a colored fluid, so when placed on any surface. Relative to the orientation of the surface to the face of the earth, the instrument reveals if a surface is: plumb within an upright position; level within a horizontal position; or at an angle, which can be marked and transferred. Reference lines are placed exactly parallel and centered to the sides and ends.

In the embodiments herein, an instrument for level and plumb determinations, includes: a sealed chamber of equal dimensions made from transparent or translucent material marked with center lines and filled with a colored fluid, so when placed on any surface. Relative to the orientation of the surface to the face of the earth, the instrument reveals if a surface is: plumb within an upright position; level within a horizontal position; or at an angle, which can be marked and transferred. Reference lines are placed exactly parallel and centered to the sides and ends.

A line and level determination system for a trenchless construction apparatus has a block assembly which is attached by welding to a lead casing to be installed with the trenchless construction apparatus. The block assembly has a water inlet, a water outlet, a tilt sensor and a light emitting device disposed within the water outlet. A water hose has a first end attached to the water inlet and a second end attached to a water source. The line and level determination system has a controller connected to the tilt sensor and the light emitting device. The controller selectively energizes the tilt sensor and the light emitting device. Data from the tilt sensor is displayed on a screen of the controller. A surveying instrument, such as a theodolite, may be utilized to determine line from the illumination of the light emitting device into the casing.