The Olympus POL-EP-3 O-Ring for PT-EP03 Underwater Housing is a spare or replacement O-ring for the underwater housing for the Olympus PEN E-PL2 camera. The O-ring is a tool that provides a watertight seal, ensuring that no water gets inside your housing and damages your camera. Resembling a thick rubber band and made of elastomeric material, the O-ring is manufactured to precision tolerances required to hold a pressure seal on your housing.
If you’re like many owners of underwater video or camera equipment, you may wonder: just how does one provide proper care to the o-ring seals that keep water safely away from my expensive electronics? This is an excellent question. The answer seems to pervade the world of SCUBA, passing from mouth to mouth, but there seems lacking a consolidation that brings all that useful advice together. Well, this brief guide will help de-mystify o-rings, their proper care, and provide a good useful summary information.
An o-ring is really nothing more than a thick rubber band! They are almost always round, or “O”-shaped, but can be rectangular, oval, trapezoidal, or any shape required to establish a watertight seal.
In cross section, they are almost always perfectly circular, although some “+” shaped o-rings are being used today as well. O-Rings are always made of an elastomeric material, which is a fancy way of saying they can stretch and deform. They can be made of natural rubber, latex, silicone, viton, or many other stretchy materials. This is an important feature of o-rings as it provides the means by which a watertight seal is formed.
O-Rings are installed where two mating surfaces come together and a watertight seal is required. Looking at two such mating surfaces (like a housing) in a cross-sectional view, with water on the outside and your electronics on the inside.
When the housing is submerged, pressure is exerted on all sides of the o-ring exposed to the water. The o-ring is then “squeezed” toward it’s only side not exposed to the water, which is into the o-ring groove created where the surfaces mate. The water itself is pushing the o-ring tight against the mating surfaces, locking itself out so it cannot enter the other side. The greater the pressure, the better the seal. This is how an o-ring seals! Rather simple and ingenious, and quite effective.