SharpEye 20/20 MPI

An Indoor Detector, Not An Industrial One

This is the distinction that decides whether the 20/20MPI is the right product, and it separates it from the rest of the SharpEye range.

Most optical flame detectors are built for process plant. Stainless steel housings, hazardous area certification, and specifications aimed at refineries and offshore installations. The 20/20MPI is built for buildings. The housing is lightweight polycarbonate, the approvals are building fire product approvals, and the applications are terminals, stations, warehouses and public spaces.

That makes it the wrong detector for a classified hazardous area and the right one for a large indoor volume where a conventional smoke or heat detector would be too slow or too high to be useful. In a building with a ten metre ceiling, smoke takes time to reach a detector at the top and heat takes longer still. An optical flame detector sees the fire directly.

Forty Three Metres From A Compact Housing

Detection reaches up to 43 metres, and that figure is the reason the product exists in this form.

Compact detectors usually trade range for size. The 20/20MPI keeps the triple infrared detection principle intact, so it holds the range while shedding the weight and the cost of an industrial housing. A single detector can cover a large concourse, a warehouse aisle or an atrium where several conventional detectors would be needed.

Field of view is 100 degrees horizontally and 90 degrees vertically. The wide horizontal spread is what allows one unit mounted at the end of a space to see down its length.

Why Triple Infrared Indoors

Triple infrared watches several infrared bands at once and correlates them. A fire produces a strong signal on the channel tuned to hot carbon dioxide, comparatively little on the reference channels, and the flicker frequency characteristic of a flame. A hot object or a sunlit surface produces similar output across all channels and no flicker.

Indoors, the false alarm sources are different from a process plant but no less real. Sunlight through glazing, halogen and metal halide lighting, radiant heaters, hot equipment and reflections off polished floors all present something for a simpler detector to respond to. In a public building a false alarm means an evacuation, so immunity matters more here than in a plant room, not less.

Two Output Models

The detector is available in two versions, and the choice is made by what the fire panel expects.

One provides alarm and fault relay outputs on a four wire connection, which suits a conventional fire alarm panel taking volt free contacts. The other provides a stepped milliamp output on a three wire source connection, which suits an analogue addressable or industrial control system reading a current loop.

RS-485 Modbus is available on both for digital integration.

Built in test runs automatically and can be triggered manually, and the warranty is three years.

The Approvals Are Building Approvals

Worth being precise about, because it decides where the detector can be used.

The 20/20MPI holds EN 54-10, which is the recognised performance standard for flame detectors used in fire detection and alarm systems, and it is CPR compliant, meaning it can be used as a construction product within a building fire system. It also holds FM approval.

What it does not carry is hazardous area certification. There is no ATEX, IECEx or Ex rating on this detector, and the polycarbonate housing reflects that. For a classified area, the SharpEye 20/20MI is the compact alternative and is available in an intrinsically safe version.

What It Will Not See

Triple infrared detects fires through the carbon dioxide their combustion produces. Hydrogen burns to water vapour and produces no signature on these channels, and metal and inorganic fires produce neither.

Where hydrogen or metal fires are part of the risk, the SharpEye 20/20ML combines ultraviolet and infrared and covers all of them, though at a shorter 15 metre range.

Where It Is Used

Airport terminals and concourses. Train stations and transport interchanges. Warehouses and distribution centres. Storage buildings and racking areas. Public buildings and civic spaces. Atriums and large retail volumes. Sports and exhibition halls. Hangars and vehicle workshops. Carparks and electric vehicle charging areas. Indoor plant and switchrooms. Museums, archives and other high value storage.