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Brand: SIEGER
Sieger Optima Plus 2108B2001 Gas Detector
Description
Overview
The Sieger Searchpoint Optima Plus gas detector is an infrared point detector for hydrocarbon gases, manufactured by Honeywell Analytics (originally Zellweger Analytics in the UK, as noted in the original listing). This Searchpoint Optima Plus gas detector carries part number 2108B2001, and the original listing describes it as a Sieger combustible gas detector, model Optima, 18-32 V DC supply, 4.5 W, Searchpoint Optima Plus.
The Searchpoint Optima Plus detects flammable hydrocarbon gases and vapours by measuring the absorption of infrared light, which gives it a fast response and fail-to-safe operation without the poisoning and drift problems of catalytic sensors. With over 100,000 infrared point hydrocarbon detectors installed worldwide, it is one of the most widely used point gas detectors in the industry.
Engineering & Design
The Searchpoint Optima Plus gas detector measures gas concentration over the range 0-100% LEL with a wide selection of hydrocarbon gas and vapour calibrations. The response is fast, with T50 below 3 seconds and T90 below 4 seconds for methane, and the optics are protected by dynamic heating control to keep the lenses free of condensation. The unit is housed in 316 stainless steel and weighs 1.6 kg.
The signal output is 4-20 mA (autosensing sink or source), with fault at 0 mA and over-range at 20-21.5 mA. Optional HART (version 7) communication over the 4-20 mA loop is available, along with optional Modbus RS485 via an XNX transmitter, giving access to diagnostics, gas readings and configuration data.
Key Features
- Infrared point hydrocarbon gas detector, range 0-100% LEL
- Fast response: T50 < 3 s, T90 < 4 s (methane)
- 4-20 mA output with optional HART version 7 communication
- Fail-to-safe operation with advanced fault diagnostics
- 316 stainless steel housing, 1.6 kg, IP66/67
- Power supply 18-32 V dc, less than 4.5 W
- ATEX, IECEx, UL and CSA hazardous area certification
Applications
- Hydrocarbon gas detection in oil, gas and petrochemical plants
- Offshore platforms and marine installations
- Gas turbine enclosures and compressor stations
- Refineries, chemical plants and fuel storage areas
Specifications
| Manufacturer | Honeywell Analytics (Sieger / Zellweger Analytics) |
| Part number | 2108B2001 |
| Type | Searchpoint Optima Plus infrared point gas detector |
| Measuring range | 0-100% LEL (hydrocarbon gases and vapours) |
| Signal output | 4-20 mA, autosensing sink or source; optional HART v7 |
| Response time | T50 < 3 s, T90 < 4 s (methane) |
| Power supply | 18-32 V dc (24 V dc nominal), < 4.5 W |
| Enclosure | 316 stainless steel, 1.6 kg, IP66/67 |
| Temperature range | -40 °C to +65 °C |
| Approvals | ATEX (Ex d IIC Gb), IECEx, UL/CSA Class 1 Div 1, EN 60079-29-1, SIL 2 |
Compatibility & Integration
The Searchpoint Optima Plus gas detector connects directly to a gas detection controller, PLC or DCS through its 4-20 mA output, and the optional HART interface allows configuration and diagnostics from a HART handheld or host system without opening the enclosure. The detector can also be integrated with Honeywell XNX transmitters for Modbus and Foundation Fieldbus communication.
Before installation, confirm the target gas and calibration, the mounting position and the hazardous area classification of the site. The detector is certified for European (ATEX), IECEx and North American (UL/CSA) hazardous areas per the manufacturer’s datasheet.
Ordering Information
To order the Sieger Searchpoint Optima Plus gas detector (2108B2001) from Seven Star LLC, quote the part number and your target gas. We confirm availability and delivery to your site in Oman or anywhere in the GCC, and we verify the part number and calibration against your application before dispatch.
Why Seven Star LLC
Seven Star LLC supplies gas detection equipment and safety instrumentation to industrial customers across Oman and the wider GCC region. Every Searchpoint Optima Plus gas detector we supply is checked against the part number before dispatch, and our team confirms the detector matches your application before you order.
FAQ
What is the Searchpoint Optima Plus 2108B2001?
The Searchpoint Optima Plus gas detector is a Sieger (Honeywell Analytics) infrared point detector for hydrocarbon gases, part number 2108B2001, operating over the range 0-100% LEL.
What are the electrical ratings of the detector?
Power supply is 18-32 V dc with less than 4.5 W consumption, and the output is 4-20 mA with optional HART version 7 communication, per the original listing and the manufacturer datasheet.
How fast does the Optima Plus respond?
The response time is T50 below 3 seconds and T90 below 4 seconds for methane, per the manufacturer datasheet.
Which hazardous area approvals does it carry?
The detector is certified to ATEX (Baseefa13ATEX0296X, Ex d op is IIC Gb), IECEx, UL/CSA Class 1 Div 1, EN 60079-29-1 and SIL 2, with marine approvals from DNV, BV, ABS and Lloyd’s Register.
Can the detector be connected to a control system?
Yes. The 4-20 mA output connects to any gas detection controller, PLC or DCS, and optional HART, Modbus (via XNX) and Foundation Fieldbus communication are available.
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How the Searchpoint Optima Plus gas detector works
The detector measures how much infrared light the gas absorbs along its optical path. The absorption changes with the gas concentration. The electronics convert the result into a 4 to 20 mA signal.
Where the Searchpoint Optima Plus gas detector is used
- Oil, gas and petrochemical plants
- Offshore platforms and marine installations
- Gas turbine enclosures
- Compressor stations
- Refineries and fuel storage areas
Selection checklist for the Searchpoint Optima Plus gas detector
- Target gas
- Calibration setting
- Measuring range
- Supply voltage
- Signal output
- HART need
- Modbus need
- Mounting point
Installation, commissioning and maintenance notes for the Searchpoint Optima Plus gas detector
Mount the detector at the chosen point and connect the supply and the signal cable. Select the gas calibration and check the output. Check the optics and the response at regular intervals.
Requesting a quotation for the Searchpoint Optima Plus gas detector
Please send the target gas, the output and the communication needs. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.
Optima Plus detector type
It is an infrared point detector for hydrocarbon gases.
Optima Plus maker
It is made by Honeywell Analytics.
Optima Plus origin
The line originated with Zellweger Analytics in the UK.
Optima Plus part number
This listing carries part number 2108B2001.
Optima Plus brand name
It is listed as a Sieger combustible gas detector.
Optima Plus installed base
More than 100,000 infrared point hydrocarbon detectors are installed worldwide.
Optima Plus infrared method
It measures the absorption of infrared light.
Optima Plus no poisoning
It avoids the poisoning problems of catalytic sensors.
Optima Plus drift
It also avoids the drift problems of catalytic sensors.
Optima Plus range
The measuring range is 0 to 100% LEL.
Optima Plus calibrations
A wide selection of hydrocarbon gas and vapour calibrations is available.
Optima Plus T50
T50 is below 3 seconds for methane.
Optima Plus T90
T90 is below 4 seconds for methane.
Optima Plus optics
Dynamic heating control keeps the lenses free of condensation.
Optima Plus housing
The housing is 316 stainless steel.
Optima Plus weight
The unit weighs 1.6 kg.
Optima Plus supply
The supply is 18 to 32 V DC.
Optima Plus power
Power use is below 4.5 W.
Optima Plus signal output
The output is 4 to 20 mA, autosensing sink or source.
Optima Plus fault signal
A fault reads 0 mA.
Optima Plus over-range signal
Over-range reads 20 to 21.5 mA.
Optima Plus HART
HART version 7 communication over the loop is optional.
Optima Plus Modbus
Modbus RS485 is optional through an XNX transmitter.
Optima Plus diagnostics
The digital link gives access to diagnostics, gas readings and configuration data.
Optima Plus fail-safe
It has fail-to-safe operation with advanced fault diagnostics.
Detector records for the Searchpoint Optima Plus gas detector
Record the calibration date, the gas reading and the date of each check.
Choosing the right Searchpoint Optima Plus gas detector output
Choose the output from the control system input and the diagnostics the plant needs.
Datasheets & Documents
- Datasheet Sieger Optima Plus 2108B2001 Gas Detector Datasheet Download
Reviews (0)
About brand
Sieger is a British gas detection brand that began in 1959 with Joshua Sieger's low-power catalytic bead sensor and became J&S Sieger Ltd in 1961. Zellweger bought the company in 1979, and Honeywell acquired it in 2005, so Sieger products are now part of Honeywell Analytics in Poole, UK. Searchpoint Optima Plus is its widely installed infrared point gas detector.
Seven Star LLC sources and supplies the Sieger Optima Plus point gas detector and its current equivalent for sites in Oman.
SIEGER company profile
| Founded | 1959, United Kingdom |
|---|---|
| Founder | Joshua Sieger |
| Ownership | Honeywell, since 2005 |
| Location | Poole, UK |
| Product families | Searchpoint Optima Plus infrared detectors, catalytic gas sensors, gas detection controllers |
Milestones
- 1959: EIC-Sieger is incorporated.
- 1961: Becomes J&S Sieger Ltd.
- 1979: Zellweger acquires Sieger.
- 2005: Honeywell acquires the business.
Sieger Optima Plus gas detector
The listed item is the Sieger Optima Plus, part number 2108B2001 (shown as 2108B2001N on some labels), known in current catalogs as the Searchpoint Optima Plus. It is a point infrared detector for flammable hydrocarbon gases and vapors. Infrared measurement is not affected by catalyst poisons and does not need oxygen, which explains its long use on oil and gas facilities, petrochemical units and tank farms in the GCC.
Ordering a Sieger gas detector: what we need
Send the complete part number from the label, including any letter at the end, since versions of this detector differ in approval and cable entry thread. Add the target gas, a nameplate photo, and the accessories in use, such as the weather protection, junction box or duct mounting kit. Tell us which controller or control system input the detector is wired to.
Facts checked against Honeywell Analytics history articles, October 2026.
Browse SIEGER products by category: Fire & Gas Detector.
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Frequently Asked Questions
What is the Searchpoint Optima Plus 2108B2001?
The Searchpoint Optima Plus gas detector is a Sieger (Honeywell Analytics) infrared point detector for hydrocarbon gases, part number 2108B2001, operating over the range 0-100% LEL.
What are the electrical ratings of the detector?
Power supply is 18-32 V dc with less than 4.5 W consumption, and the output is 4-20 mA with optional HART version 7 communication, per the original listing and the manufacturer datasheet.
How fast does the Optima Plus respond?
The response time is T50 below 3 seconds and T90 below 4 seconds for methane, per the manufacturer datasheet.
Which hazardous area approvals does it carry?
The detector is certified to ATEX (Ex d IIC Gb), IECEx, UL/CSA Class 1 Div 1, EN 60079-29-1 and SIL 2, with marine approvals from DNV, BV, ABS and Lloyd’s Register.
Can the detector be connected to a control system?
Yes. The 4-20 mA output connects to any gas detection controller, PLC or DCS, and optional HART, Modbus (via XNX) and Foundation Fieldbus communication are available.
Reviews
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