The Open Path Gas Detectors include the two series of ds900 and ds700 which we will explain in this post.

Open Path Gas Detector ds 900 Series Laser Detector:

The SafEye Quasar 900 series features the latest open path IR technology that detects a wide range of hydrocarbon gases including alkanes (methane to hexane) and ethylene.
The model can travel up to 660 feet (200 meters) in length, and you can use Quasar 900 models to protect high-risk installation.
Reliability and performance are key, and trust this product with SIL2 verification and performance testing, and having FM and EN standards.

Why Open Path Gas Detectors?

Spectrex invented the xenon flash lamp design that revolutionized the open-path gas detection market, which, until then, was plagued by false alarms due to the drawbacks of the previous designs.
Now, Open path detectors complement the use of individual point detectors, take executive action and offer many significant benefits including:
• Wider area coverage
• Most likely method to pick up any leak
• Very high speed of response
• No unrevealed failure modes
• Beam block warning
• Detector location is less critical
• Size of gas hazard indicated

Applications include:

• Offshore platforms & FPSOs
• Petrochemical plants
• Chemical processing plants
• Gas filling and distribution terminals
• Gas transport and pipelines
• Large storage areas & buildings
• Perimeter monitoring

Installation Options

QUASAR OFFERS OPTIONS FOR YOUR INSTALLATION:
• 0-20mA analog output with HART capability
• RS485 Modbus, where up to 256 detectors can be linked

Worldwide Approvals

• Hazardous area (Zone 1) FM/FMC, ATEX, IECEx, GOST R Inmetro
• Performance (3rd party):
FM 6325 approved by FM
EN60079-29-4 tested by FM
• Reliability:
SIL2 (TUV)

HART

HART capabilities within the Quasar 900 can provide digital communications between the field and the safe area.
This can provide real time information on the status of an individual detector as well as configuration and historical data of each device, without the need for extra cable cores.
A key feature of HART is that digital signals are transmitted on the same two wires as the 0-20mA current signal.
Useful and useable information available via HART includes:
• Display set-up
• Reconfigure set-up – such as gas
calibration, heater control, address
• Display detector status and definition
• Perform detector diagnostics
• Troubleshooting
• View Event Log

Open Path Gas Detector ds 700 Series Laser Detector:

این تصویر نشان می دهد که چگونه ماتریس آشکارسازهای نوع نقطه ای می توانند نشتی را از دست بدهند یا در نهایت فقط سطح گاز رقیق شده را مشاهده کنند در حالی که SafEye 700S Open-Path ، در این حالت 20٪ LEL x 7 m = 1.4 LEL.m را اندازه می گیرد.

Open-path Gas Detection Concepts

Not all gas clouds are hazardous – only if a flammable gas cloud or plume is wide enough to allow flame acceleration to speeds greater than 100 m/sec does it become a significant threat.

•Just as an athlete performing the long jump needs a run-up distance, so too a flame front needs distance to reach the velocities which cause the damaging effects of over pressure, pressure pulse and windage.

•The generally accepted quantity of gas that creates the potential to cause consequential damage if ignited is a cloud of the size 5 m diameter a stoichiometric concentration (about200% LEL).

• To provide a safety margin, this concentration is halved to 100% LEL. Thus an open path beam traversing this cloud would indicate 5 LEL.m.

•Location of the SafEye 700S Open-Path Gas Detector is less important than with point type detectors as it provides a warning alarm from a diluted gas cloud and does not need to be close to the leakage source.

• Point type detectors measure gas at their location in terms of % LEL, whereas open-path gas detectors measure the amount of gas anywhere along the length of the path, in terms of the integral of concentration and length (LEL x meters).

Open-Path Applications:

•Offshore Oil & Gas drilling and production
•Petrochemical and Chemical storage and ذproduction areas
•Storage & loading of hazardous materials and waste areas
•Engine & Turbine air intake and modules
•LNG-LPG storage, pumping and filling
•Fence-line emission monitoring
•Storage Tank Farm protection
•Paint industries, including paint-booths
•Bus terminals (natural gas powered)
•Waste disposal and processing