SharpEye 20/20Q

Four Sensors, Not Three

QuadSense is the point of this detector and the name explains it.

A triple infrared detector compares three infrared bands. A real flame flickers in a characteristic way and radiates across those bands in a particular ratio. Background sources such as hot surfaces, sunlight on metal and arc welding do not match that pattern across all three at once.

The 20/20Q integrates four infrared sensors across four bands between 4 and 5 micron. The extra channel gives another point of comparison, which improves the separation between a genuine flame and background radiation that happens to resemble one.

The practical result is 45 metres on a 0.1 square metre gasoline or n-heptane fire at the highest sensitivity, with a detection response typically under 5 seconds.

Three Enclosures, One Detector

The enclosure is an ordering option rather than a different product, and the choice is about weight, cost and conditions.

The engineered polymer version is the one to understand, because the weight difference is substantial. At 280 grams against 750, it is roughly a third of the weight, and a matching polymer tilt mount weighs 120 grams against 700 for stainless steel.

On a ceiling mount, a long bracket or a retrofit onto existing structure, that difference changes what has to be engineered to support it. Emerson position the polymer enclosure for light industrial and non-corrosive environments, so it is the cost effective choice for easier conditions rather than a harsh environment option.

Where the atmosphere is corrosive, or where the detector will take knocks, aluminium is the answer.

The Direct Replacement For The 20/20MPI

The 20/20Q engineered polymer version replaces the 20/20MPI.

The important part for anyone with MPIs installed is that it uses the same wiring and the same base footprint. A detector can be swapped without rewiring, re-drilling or altering the installation.

Compared with the 20/20MPI, it brings the current 20/20Q platform, QuadSense detection, improved performance and reliability, and better false alarm immunity. If you have 20/20MPI detectors installed, talk to our Technical Consultants about planning the changeover.

Factory Calibrated For Life

Worth drawing out, because it removes a recurring cost rather than a one off one.

The detector is factory calibrated for life, so there is no periodic recalibration to schedule, budget or arrange access for. Over a fifteen or twenty year installation across a building full of detectors, that is a considerable saving in service visits.

It does not remove functional testing. The infrared built in test runs continuously and verifies the optics and the electronics, but as on any flame detector it does not fire the outputs. Proving the relays, the panel and any suppression release still needs an external flame simulator, and the FS-1100 is listed as the accessory for it.

Five Sensitivity Levels

Sensitivity is selectable at 3, 10, 20, 30 and 45 metres.

That matters more than it sounds. A detector set for 45 metres in a small plant room is watching a volume far larger than the area it protects. That gives more opportunity for a distant background source to be seen. Setting the sensitivity to the area actually being covered improves false alarm performance rather than degrading protection.

An internal event log recorder holds the history, which is what you need when investigating why a detector alarmed or faulted three weeks ago.

Outputs And Integration

Three output paths are available together. Relays for fault and alarm, rated 2 amps at 30 volts DC. A stepped 0 to 20 milliamp output, configurable, with distinct levels for fault, built in test fault, normal, warning and alarm. And RS-485 Modbus for integration into a controlled installation.

The stepped current output is the useful one for retrofit, because a single pair of wires carries five distinguishable states back to a panel.

Supply is 24 volts DC nominal across a 12 to 32 volt range, drawing 25 milliamps and 0.6 watts in normal operation. Universal wiring is offered as an ordering option to simplify specification.

Where It Is Used

Emerson’s own application list is worth reading as written, because it describes a building fire detector rather than a process one.

Airport terminals. Train stations and terminals. Storage areas and archives. Shopping centres. Hospitals. Car parking towers and garages. Public buildings. Banks and offices. Historical and cultural sites. Aircraft hangars. Cable tunnels. Automotive parts manufacturing.

For a classified area, the SharpEye 40/40 range carries hazardous area approval and reaches considerably further.

Detection Ranges

At the highest sensitivity setting, for a 0.1 square metre pan fire.

Methane and LPG figures are for a 0.75 metre high, 0.25 metre wide plume fire.