Searchline Excel

Two Range Options, One Detector

The Searchline Excel comes in two versions that differ in one way only: path length.

Detection range, response time, operating temperature, power, outputs, repeatability, drift, warm up and ingress protection are the same on both. So the choice is about geometry, not performance. Measure the beam path you need to cover, and the version follows.

The two overlap between 60 and 120 metres. In that band either will work, and the choice usually comes down to what else is being installed on site, since one model type means one set of spares.

Seeing Through Fog Is the Whole Argument

An open path detector that stops working in bad weather fails at exactly the moment conditions are worst and attention is lowest.

Fog, rain, snow and dust all scatter infrared, and a beam crossing 200 metres of it loses a lot of signal.

Honeywell’s answer is optical. Advanced transmitter and receiver optics keep monitoring in thick fog long after other open path detectors, NDIR or laser based, stop providing coverage. Where the signal does degrade, advanced diagnostics report window clarity and alignment accuracy, so a real problem can be told apart from the weather.

For an Australian site, that means a coastal fog bank or a Pilbara dust event doesn’t open a gap in your fire and gas coverage.

Calibration Free

Open path detectors are usually the hardest instruments on a site to calibrate. They’re mounted high, aimed across a distance, and applying test gas across a beam is awkward.

The Searchline Excel is calibration free. There’s no routine gas application, no annual calibration visit to each beam and no ladder work to schedule.

Combined with automatic reporting and full logging of alarms, events and maintenance actions, that changes what an open path installation costs to own. The detector keeps its own record and tells you when it needs attention, rather than needing a scheduled visit to confirm it’s working.

Bluetooth, Not a Screwdriver

Setup and maintenance run over Bluetooth. Pair the detector with Honeywell’s intrinsically safe ruggedised phone, then use the Honeywell Fixed Platform App to interact with it.

Bluetooth range is up to 20 metres, depending on the device and conditions. So a detector mounted high on a pole can be checked from the ground, in a classified area, without opening an enclosure.

Through the app, you get readings, device status, configuration and diagnostics. On a site with twenty beams, that’s the difference between a day of access equipment and an afternoon walking the site with a phone.

Alignment and Mounting

Alignment is where open path installations go wrong, and where the labour goes.

The Honeywell Fixed Platform Universal Mount, with its advanced alignment scope, makes the mechanical installation straightforward. The diagnostics then report alignment accuracy continuously, rather than leaving you to discover drift when the detector faults.

Continuous alignment reporting matters more at long range. A small angular error over 330 metres becomes a large error at the receiver.

The transmitter and receiver each weigh about 6 kg and measure 103 mm in diameter x 325 mm x 180 mm.

Reading LEL Metres

Both versions read 0 to 5 LEL metres, linearised, with recommended alarms at 1 LEL.m (low) and 3 LEL.m (high).

LEL metres measures the total gas along the beam, rather than the concentration at one point. It reports the quantity of gas in the monitored line, so a wide thin cloud and a narrow dense one can read the same. On a large site, that’s the useful measurement, because what matters is whether gas is in the area.

Repeatability is ±0.4 LEL.m. Temperature drift from -40°C to +65°C is ±0.2 LEL.m at zero and ±0.5 LEL.m at 3 LEL.m.

Integration

Outputs include 4-20 mA with HART, Modbus, Bluetooth, and three relays for fault, alarm 1 and alarm 2. Relays are rated to 32 VAC or VDC at 2 A resistive.

The analogue signal carries diagnostic states, not just a reading. Normal operation is 4 to 20 mA, with 1 mA for fault, 2 mA for inhibit, 3 mA for warning and 21 mA for over range. A control system reading that loop can tell a fault from a clean zero, which a plain 4-20 mA output can’t.

Power is 24 VDC nominal, across 18 to 32 VDC. Consumption rises as the temperature falls, so a cold climate installation needs the supply sized for the low temperature figures.

Certified for Hazardous Areas

Both versions are certified IECEx ULD 18.0016X, Ex db ia IIC T4 Gb for flameproof installations, or Ex db eb ia IIC T4 Gb for increased safety installations, with Ex tb IIIC for dust. They also carry ATEX and cULus approval, and SIL 2 certification by TÜV SÜD to EN 61508.

Marine and Offshore

Both versions are rated to DNVGL-CG-0339 Location Class B for temperature and humidity, and to IP66 and IP67, Type 4X to NEMA 250.

They’re also tested for resistance to salt mist and sulphuric atmosphere. For offshore platforms, FPSOs, marine terminals and coastal plant, that combination is what separates a detector that survives from one that corrodes.

Where It’s Used

Refineries and petrochemical plant, upstream and downstream, LNG production, storage and transfer, onshore terminals and tank farms, offshore platforms and FPSOs, pipe racks and process modules, compressor houses and stations, tank bunds and loading areas, perimeter and fence line monitoring, site boundary monitoring, and mining and mineral processing where hydrocarbon fuel is stored in volume.