Acetylene Analyzers — TDLAS for Process, DGA & Synthesis Feed
Laser selectivity for C₂H₂ across welding gas QA, transformer DGA, and chemical synthesis feed control.
TDLAS acetylene analyzers for continuous C₂H₂ monitoring in welding-gas manifolds, chemical synthesis feeds (VAM / 1,4-BDO), transformer dissolved-gas analysis, and semiconductor CVD precursor qualification — where narrow-line laser absorption resolves acetylene from hydrocarbon and moisture background that constrain broadband sensors.
How TDLAS Works for C₂H₂
Tunable Diode Laser Absorption Spectroscopy
A tunable diode laser scans across a selected C₂H₂ absorption line in the near-IR (~1.5 μm). The narrow laser linewidth targets the acetylene overtone feature directly, resolving it from C₂H₄, C₂H₆, CH₄, and moisture background — delivering reagent-free, single-species measurement with fast T90 response.
- TDLAS single-line laser absorption — reagent-free optical cell; filters and span gas remain service items
- Multi-range firmware covers DGA ppm to process %vol without optics change
- Engineered for extractive sample loops in hydrocarbon / synthesis gas matrices
- Hazardous-area enclosure scope reviewed per refinery / fuel-gas / chlor-alkali project
TDLAS C₂H₂ Sensing Principle
Four C₂H₂ Sensing Paths at a Glance
Process TDLAS is the default for continuous in-line C₂H₂ measurement. Lab/DGA bench-top TDLAS covers laboratory confirmation and DGA inter-comparison. GFC NDIR is listed as a legacy conditional reference. Portable field screening is an engineering-path option without a dedicated catalogue SKU.
Process TDLAS
Default In-Line Standard
ZS8100-C2H2: continuous extractive TDLAS for welding-gas manifolds, synthesis feed, CVD precursor, and DGA gas-phase duty — multi-range ppm to %vol, with hazardous-area enclosure scope reviewed per project.
Lab / DGA Bench-Top TDLAS
DGA Confirmation & Metrology
Bench-top TDLAS for DGA laboratory confirmation, inter-comparison against oil-gas extraction samples, and periodic cylinder mixture audit — tighter multi-pass cell, metrology-grade calibration reports. Available by project review alongside the ZS8100-C2H2.
GFC NDIR Reference
Legacy / CEMS Slot Reference
GFC correlation NDIR may be specified as a CEMS-slot reference for certain legacy installations; note that broadband IR selectivity is significantly lower than TDLAS for C₂H₂ in hydrocarbon-rich matrices.
Portable Field Screening
Engineering Review Required
Portable C₂H₂ screening for cylinder spot-check and leak surveys. No dedicated catalogue SKU on this page — scoped per application via engineering review.
Extractive Process vs Bench-Top Lab vs Portable Field Deployment for C₂H₂
ZS8100-C2H2 — Extractive TDLAS Process Analyzer
A conditioned sample line draws acetylene-containing process gas through the ZS-SCS-600 cool-dry chain or ZS-SCS-800 heated line (application-dependent), and the multi-pass TDLAS cell measures C₂H₂ continuously — the standard configuration for welding-gas headers, synthesis feed loops, CVD precursor qualification, and DGA gas-phase extraction.
ZS-SCS-600 cool-dry (coalescing filter + chiller to ~5 °C dew point + 2 μm particulate catch) for welding-gas and most process duty. ZS-SCS-800 heated line for applications where upstream scrubbers or wet traps could condense on the cell window. Sample pressure: −30 to +500 mbar g.
- Welding-gas manifold and blending-skid purity (CGA G-1.1)
- VAM / 1,4-BDO synthesis feed-window control
- DGA: gas-phase side of oil-gas extraction module (IEC 60567 / ASTM D3612)
Bench-Top TDLAS — Laboratory Confirmation
The bench-top TDLAS configuration is specified for DGA laboratory confirmation, inter-comparison, and periodic audit of portable cylinder mixtures. It trades continuous-duty packaging for a tighter multi-pass cell and metrology-grade calibration reports — the preferred choice when documentation sign-off or laboratory inter-comparison matters more than a continuous DCS output. Note: this bench-top lab path is referenced here as a companion instrument, available by project review rather than as a standalone catalogue SKU on this page.
Bench-top laboratory environment; extracted DGA gas samples per IEC 60567 / ASTM D3612, or reference cylinder gas. Stable temperature, low vibration, clean power supply.
- DGA laboratory confirmation and inter-comparison for transformer fault diagnosis
- Periodic audit and metrology reporting of cylinder acetylene mixtures
Field Portable (Engineering Path)
Portable C₂H₂ screening instruments for cylinder spot-checks and leak surveys in the field. No dedicated GESHINE catalogue SKU is listed on this page for portable C₂H₂ — applications with portable requirements are handled through an engineering review to specify the appropriate handheld configuration and confirm instrument selectivity against the local hydrocarbon background.
Built-in pump, direct probe sampling. The instrument’s selectivity against C₂H₄, C₂H₆, and CH₄ background must be verified for the target application before field deployment.
- Cylinder delivery spot-check and leak survey in storage / dispatch areas
- Cross-checking of installed fixed analyzers during commissioning
Portable field screening: lowest per-event cost for cylinder delivery checks and commissioning cross-checks; requires engineering review for selectivity in hydrocarbon-rich fields.
ZS8100-C2H2 in-line: higher initial conditioning investment, but lowest cost-per-measurement over a multi-year continuous welding-gas or synthesis feed duty cycle.
Bench-top TDLAS: periodic laboratory confirmation and DGA inter-comparison — most economical when deployed alongside continuous ZS8100-C2H2 process analyzers.
Why TDLAS for C₂H₂ Measurement
Broadband NDIR cannot reliably resolve acetylene from C₂H₄, C₂H₆, and CH₄ at DGA ppm concentrations. TDLAS targets a specific C₂H₂ absorption line from the outset — it is the primary technology choice for C₂H₂, not a post-hoc upgrade from an NDIR baseline.
| Dimension | Broadband NDIR | GFC NDIR | TDLAS — Chosen (ZS8100-C2H2) |
|---|---|---|---|
C₂H₂ selectivity | Band overlap with C₂H₄, C₂H₆, CH₄ | Improved vs broadband, still limited at ppm level | Single laser line on C₂H₂ overtone — Voigt profile fitting minimises hydrocarbon cross-talk |
★DGA detection limit | Typically >5 ppm (insufficient for early-warning DGA) | Better than broadband; SCS still needed | <0.5 ppm DGA-useful — suited to IEC 60599 C₂H₂ early-warning threshold |
★Response time (T90) | 15 – 60 s (SCS lag) | 10 – 30 s | <5 s |
Installation format | Extractive + SCS | Extractive + SCS | Extractive; hazardous-area enclosure reviewed per project |
★Multi-range firmware | Not typical across ppm–%vol span | Not typical | DGA ppm to process %vol — single optics, field-reconfigurable |
Sample conditioning | Cool-dry chiller + coalescing filter | Cool-dry chiller + coalescing filter | ZS-SCS-600 cool-dry or ZS-SCS-800 heated — selected by moisture and oil-mist profile |
Hazardous area | Project review | Project review | Certificate package confirmed against selected enclosure and site classification |
★Reagent / consumable in cell | Optical cell — no reagent (but wide-band filter service) | Correlation filter cell service | Optical cell — no reagent; filters and span gas are service items |
★ marks the four dimensions where TDLAS delivers a meaningful advantage over broadband methods specifically for C₂H₂ measurement.
C₂H₂ Analyzer Selection by Application, Matrix and Form Factor
Three application paths determine which C₂H₂ analyzer configuration fits your project: welding gas purity, transformer DGA, or chemical synthesis and semiconductor CVD. Each path carries specific sample conditioning, concentration range, and form-factor requirements.
Welding Gas & Industrial Purity Monitoring
Industrial acetylene cylinder and blending-skid purity verification to CGA G-1.1 commodity specifications requires a continuous in-line TDLAS analyzer that can report C₂H₂ concentration at %vol levels with fast response for header control. The ZS8100-C2H2 extractive TDLAS process analyzer, paired with a ZS-SCS-600 cool-dry conditioning chain to remove oil mist from cylinder manifolds, is the standard configuration for metallurgical welding operations. The analyzer reports C₂H₂ %vol plus impurity ppm excursions against the commodity purity specification, with 4–20 mA and Modbus output for integration into the blending-skid control loop. See the TDLAS technology rationale for why TDLAS is specified here rather than broadband NDIR.
Transformer Dissolved-Gas Analysis (DGA)
IEC 60599 identifies C₂H₂ as a key fault-gas signature for electrical arcing and thermal faults in power transformers. Early-warning DGA requires detection at sub-ppm to low-ppm levels — a range where broadband NDIR suffers from hydrocarbon background cross-talk and insufficient detection limit. The ZS8100-C2H2 in-line TDLAS analyzer is deployed on the gas-phase side of a validated oil-gas extraction module (IEC 60567 / ASTM D3612), delivering continuous live C₂H₂ readings to the grid control center without the multi-day lab-return cycle of traditional DGA sampling. A bench-top TDLAS provides complementary DGA laboratory confirmation and inter-comparison. Online DGA without a validated oil-gas extraction module is a Conditional engineering-review path, not a drop-in catalogue offering.
Chemical Synthesis Feed & Semiconductor CVD
Acetylene is a critical precursor in vinyl acetate monomer (VAM) and 1,4-butanediol (1,4-BDO) synthesis, where feed-window C₂H₂ purity directly affects catalyst performance and yield. In semiconductor manufacturing, acetylene CVD precursor gas must meet stringent purity specifications before release from the gas cabinet. Both applications operate in matrices that include residual C₂H₄, C₂H₆, and CH₄ — where the TDLAS single-line selectivity of the ZS8100-C2H2 provides a clear advantage over broadband sensing. For chlor-alkali plant duty or other inherently hazardous environments, hazardous-area enclosure scope should be reviewed and documented per project. Contact the application engineering team with your compound list, concentration range, and background matrix to confirm the correct sample conditioning configuration.
Browse Acetylene Analyzers
ZS8100-C2H2 — TDLAS in-line process analyzer. A bench-top TDLAS lab configuration is referenced as a laboratory-confirmation companion.
In-line ProcessZS8100-C2H2 · TDLAS
ZS8100-C2H2 Process Acetylene Analyzer
TDLAS tunable diode laser acetylene analyzer for welding gas purity, chemical-synthesis feed (VAM / 1,4-BDO), and extractive transformer DGA workflows
- Range
- 0–100 ppm / 0–1000 ppm / 0–5 %vol (multi-range)
- Accuracy
- ±2 % FS or ±1 ppm (whichever greater)
- Response T90
- <5 s
- Detection Limit
- <0.5 ppm (DGA-useful)
- Output
- 4–20 mA / RS-485 Modbus / HART
Where C₂H₂ Measurement Matters in the Plant
From transformer early-warning DGA to welding-gas QA and synthesis feed control — acetylene measurement in three distinct industrial contexts.
Power Transmission & Transformer DGA
Dissolved-gas analysis (DGA) on power transformers identifies C₂H₂ as an early-warning fault-gas signature for electrical arcing per IEC 60599. Continuous TDLAS C₂H₂ monitoring on the gas-phase side of oil-gas extraction modules reduces the early-warning window from days to minutes, compared with lab-return DGA sampling cycles. ZS8100-C2H2 in-line analyzers and bench-top TDLAS laboratory confirmation are commonly deployed together in substation DGA architectures.
See power applicationsMetallurgy & Welding
Industrial acetylene cylinder manifold and blending-skid purity verification to CGA G-1.1 commodity specifications is a standard application for gas-shielded welding, cutting, and thermal spraying operations in steel and fabrication plants. The ZS8100-C2H2 TDLAS process analyzer monitors C₂H₂ %vol on the header with ZS-SCS-600 cool-dry conditioning to remove oil mist from cylinder plumbing, reporting impurity ppm excursions against the commodity purity window in real time.
See metallurgy applicationsChemical Process & Semiconductor
Acetylene is a feed-window reactant in vinyl acetate monomer (VAM) and 1,4-butanediol (1,4-BDO) synthesis, and a CVD precursor gas in semiconductor manufacturing. Both applications require ppm-level C₂H₂ monitoring in hydrocarbon matrices where selectivity against C₂H₄, C₂H₆, and CH₄ is critical. The ZS8100-C2H2 TDLAS analyzer can be scoped for hazardous-area enclosure review where the selected site classification requires it.
See chemical applicationsWhy GESHINE for C₂H₂ Analyzers
TDLAS laser selectivity, DGA-ready extractive architecture, multi-range firmware, and application engineering support for welding gas, synthesis feed, and transformer DGA workflows.
Laser Selectivity
TDLAS single-line scanning targets the C₂H₂ near-IR overtone feature — Voigt profile fitting minimises cross-talk from C₂H₄, C₂H₆, CH₄, and moisture that limit broadband IR sensors in DGA head-space and synthesis feed matrices.
DGA-Ready Architecture
Gas-phase extractive design pairs with IEC 60567-compliant oil-gas extraction modules for transformer DGA workflows. The ZS8100-C2H2 measures on the extracted gas side; DGA sample handling and oil-gas extraction are scoped per project.
Multi-Range Firmware
The same optical hardware spans DGA ppm detection to welding-gas and synthesis-feed %vol measurement — field-reconfigurable without optics change. ZS8100-C2H2 covers 0–100 ppm / 0–1000 ppm / 0–5 %vol multi-range in a single platform.
Application Engineering Support
Sample conditioning design for welding-gas manifolds or DGA extraction loops, CVD precursor application scoping, and hazardous-area enclosure review — direct access to the engineering team from inquiry through commissioning.
Acetylene Analyzer Questions, Answered
Key questions on TDLAS C₂H₂ measurement for transformer DGA, welding-gas QA, and synthesis feed applications.
Can the ZS8100-C2H2 perform online transformer DGA without an oil-gas extraction module?
IEC 60599 defines DGA against gases dissolved in transformer oil, not free head-space, so online DGA always needs an oil-to-gas extraction stage — head-space equilibrium or polymer membrane — to strip dissolved C₂H₂ into a carrier stream that TDLAS can read. Direct laser interrogation of the oil matrix remains a research-grade concept and has not displaced extraction modules in field service. The ZS8100-C2H2 ships tuned for the gas-phase side of the loop; pairing with a validated oil-gas extraction skid is therefore a Conditional engineering-review path rather than a drop-in capability, and extracted-sample DGA per IEC 60567 / ASTM D3612 remains the principal workflow.
How does TDLAS separate C₂H₂ from C₂H₄ / C₂H₆ / CH₄ overlap in DGA head-space?
The near-IR C₂H₂ overtone feature at ~1.5 μm is narrower than anything a broadband filter-photometer sees. The instrument tunes across the selected line centre, fits a Voigt profile, and subtracts adjacent hydrocarbon wings so C₂H₄, C₂H₆ and CH₄ are handled as part of the declared DGA background instead of being treated as arbitrary mixtures. Accuracy is specified with a representative hydrocarbon background per IEC 60567 sample preparation; unusually rich backgrounds (for example >5 %vol CH₄) are handled by a dedicated application calibration rather than the default factory calibration.
What sample conditioning does the welding-gas manifold application need?
Metallurgical acetylene feed arrives dry but is typically entrained with oil mist from cylinder manifolds and blending skids. For header / blending-skid QA, the ZS-SCS-600 cool-dry chain is typically specified — coalescing filter, chiller to a stable 5 °C dew point, and 2 μm particulate catch — ahead of the analyzer cell. Heated sampling (ZS-SCS-800) is specified only when an upstream scrubber or wet-trap could condense on the cell window. CGA G-1.1 commodity-acetylene purity governs the spec envelope; the analyzer reports C₂H₂ %vol plus impurity ppm excursions against that spec.
What calibration cadence should I plan for routine process duty?
Under the GESHINE maintenance plan the TDLAS signal chain runs an automatic zero-check against a sealed reference cell at user-settable intervals (typical daily) and a manual span verification with a certified C₂H₂ mixture every 6 months for process duty, quarterly for DGA-rated service. Because the principle is optical-only (no chemistry consumable) there is no electrochemical cell or reagent to swap; the dominant service items are the laser module and the window purge, both field-replaceable without cell re-alignment.
When should I choose the bench-top TDLAS lab path instead of the in-line ZS8100-C2H2?
The ZS8100-C2H2 is intended for continuous in-line / on-skid duty with hazardous-area enclosure scope reviewed per project, 24/7 operation, and 4–20 mA / Modbus hand-off to SCADA. The bench-top TDLAS lab path is specified for DGA laboratory confirmation, inter-comparison, and periodic audit of portable cylinder mixtures — it trades continuous-duty packaging for a tighter multi-pass cell and metrology-grade calibration reports. Operations logging transformer DGA trend data online run the in-line ZS8100-C2H2; labs signing off reference samples run the bench-top lab unit. Many utilities deploy both in parallel.
What is the measurement range for DGA applications versus process applications?
The ZS8100-C2H2 multi-range firmware covers 0–100 ppm (DGA early-warning), 0–1000 ppm (DGA extended), and 0–5 %vol (process welding-gas / synthesis feed) — all using the same TDLAS optical cell without hardware change. The DGA-useful detection limit of <0.5 ppm allows C₂H₂ early-warning against the IEC 60599 guidance thresholds. The %vol range serves commodity-grade welding-gas purity and chemical synthesis feed monitoring.
Which standards govern acetylene measurement in transformers and welding gas?
For transformer DGA: IEC 60599 (interpretation of dissolved-gas analysis results), IEC 60567 (sampling dissolved gases from oil-filled equipment), ASTM D3612 (dissolved-gas analysis by gas chromatography), and IEEE C57.104 (guide for interpretation of gases generated in mineral-oil-immersed transformers). For welding-gas purity: CGA G-1.1 (commodity acetylene specification). For the analyzer itself: EN 61326-1 (EMC) and CE marking are reviewed as target scope. Hazardous-area approval requirements are application-dependent and should be confirmed against the selected enclosure and site classification.
Request a Quote for Acetylene Analyzers
To configure the optimal C₂H₂ analyzer for your application, please have these details ready:
- Target gas: C₂H₂ concentration range (ppm for DGA / %vol for welding gas or synthesis feed)
- Application: process monitoring / transformer DGA / laboratory confirmation / CVD precursor
- Background matrix: hydrocarbon content (C₂H₄, C₂H₆, CH₄) and moisture level at sample point
- Sample temperature, pressure, and oil-gas extraction module details (if DGA application)
- Installation form: in-line process (ZS8100-C2H2) / bench-top lab (bench-top TDLAS) / both
- Hazardous area: site classification and enclosure documentation scope, if applicable
- Output protocols: 4-20 mA, RS-485 Modbus, HART
- Calibration gas availability: certified C₂H₂ mixture traceable to project range
Get C₂H₂ Application Expert Consultation
Our application engineers specialize in TDLAS acetylene measurement for transformer DGA, welding-gas QA, synthesis feed control, and CVD precursor qualification — from sample conditioning specification through commissioning.