Abstract: According to some embodiments, a pressure tolerant camera system includes: an enclosure filled with an incompressible fluid and having a viewport through which light can pass; a digital image sensor provided within the enclosure; and a plurality of mirror lenses provided within the enclosure and arranged to reflect light from the viewport onto the digital image sensor.

Abstract: The invention discloses a selectable offset image wedge assembly and various methods for making and for use with any optical system having a circular lens and an objective, comprising a housing with a rear-facing end that mounts onto the objective and a forward-facing end with a circular wedge lens mounted therein that is coaxially aligned with the circular lens of the optical system, wherein, the wedge is adjustable to any predetermined clocking position after detachment from the optical system, allowing quick and repeated reattachment to the optical system to an approximately exact vertical orientation of a first image produced by the wedge lens and a second image produced by the circular lens of the optical system.

Abstract: The invention discloses a selectable offset image wedge assembly and various methods for making and for use with any optical system having a circular lens and an objective, comprising a housing with a rear-facing end that mounts onto the objective and a forward-facing end with a circular wedge lens mounted therein that is coaxially aligned with the circular lens of the optical system, wherein, the wedge is adjustable to any predetermined clocking position after detachment from the optical system, allowing quick and repeated reattachment to the optical system to an approximately exact vertical orientation of a first image produced by the wedge lens and a second image produced by the circular lens of the optical system.

Abstract: A parametric emissions monitoring system for monitoring stationary engine/compressor units coupled to a pipeline provides, in a reciprocating embodiment, reliable and accurate determinations of emission levels for NO.sub.x, CO, and total hydrocarbons (THC) from an emissions matrix primarily as a function of engine speed and engine torque. Validation of the determined emissions level is provided by comparing the values of a set of actual engine operating parameters with a respective value in a set of calculated engine operating parameters to determine whether the deviation of the actual operating parameter from the expected operating parameter is within a defined range, and thus whether the engine is operating within a defined control envelope. Each set of engine operating parameters includes spark ignition timing, fuel rate, and air manifold pressure.