The N88-2-M Pit Gauge with a 63.5 mm (2.5") basic blade is the perfect tool to determine the amount of surface corrosion on metal constructions like pipelines, support structures, storage tanks, drill pipes, steel bridges, aircraft components or concrete structures.
The measurements can be focused on local corrosion areas but with the proper extensions the corrosion inspector can span larger areas to determine the material loss and/or dents over these larger areas.
This pit gauge has a spring loaded lever that makes it very suitable for fast inspection of various surfaces.
The blades are interchangeable and can be height adjusted.
Our Pit Gauges assure compliance with vessel, pipeline, tank and OCTG specifications for corrosion and erosion depth measurement.
The complete kit includes:
Contact Point (or Standard) – N88-S. This Contact Point was designed for general Corrosion Testing, and remains the most universal in use. The #1 tapers down, over its length, to a blunt point that is less than 0.75 mm (0.030”) in Diameter.
Contact Point (or Conical) – N88-C. This Contact Point is more robust than the Standard Contact Point, due to its much larger size. The #2 Contact Point is recommended when a large amount of Scanning is being performed. The #2 tapers down, over its length, to a rounded point that is approximately 0.5 mm (0.020”) in Diameter.
Needle Point – N88-N The Needle Point was developed to satisfy the needs of Corrosion Coupon Evaluations, where pits are shallow and small in diameter. The #3 Needle Point tapers down to a very sharp point, so as a result they tend to be very delicate.
The vertical position of the Contact Point, needs to be Zeroed with respect to the Knife Edge of the Blade. Zeroing can be accomplished in two ways; by adjusting the Height of the Dial Indicator in the Blade; or by Rotating the outer Bezel Scale while pressing on the Plunger onto a flat surface.
Loosen the Fastener(s) holding the Dial Indicator in place. Hold the Blade firmly on a Flat Surface, and gently press the body of the Dial Indicator down until the contact point touches the flat surface. Carefully re-tighten the Clamp Fastener(s) or the Set Screw. Any fine zeroing can be done by rotating the Bezel Scale on the Dial Indicator
To quickly check the Zero Point of the Dial indicator, place the Blade on a representative smooth surface. Gently press the Plunger, until the contact point touches the surface. While the contact point is on the surface, loosen the Bezel Lock, and rotate the Bezel Scale until it reads '0' with respect to the pointer.