Frequently Asked Questions (FAQ)
What is TDLAS and how does it work?
TDLAS (Tunable Diode Laser Absorption Spectroscopy) measures how a specific wavelength of laser light is absorbed by gas molecules along a path, providing fast, selective concentration readings. TDLAS uses narrow-band lasers tuned to molecular absorption lines from the HITRAN database. When the beam passes through gas, the detector records intensity loss. From Beer–Lambert’s law, concentration is derived precisely, even in humid or varying pressure environments. Because it measures directly in-situ or via a short extractive path, response is sub-second and maintenance minimal.
| Measurement range | Accuracy | Response time | Typical gases |
|---|---|---|---|
| ppb → % (species-dependent) | ±0.5 – 1 % of reading | < 1 s (inline) / 1–3 s (extractive) | CH₄ · NH₃ · H₂S · HF · CO₂ |
What are the advantages of TDLAS over NDIR gas analyzers?
TDLAS offers higher selectivity, faster response, and lower maintenance than NDIR, but it’s more complex to specify correctly. NDIR uses broadband infrared and is best for simple CO₂/CO/CH₄ detection. TDLAS targets specific spectral lines, reducing cross-interference and improving detection limits.
TDLAS systems also offer sub-second response times and low drift, with no consumables to replace.
| Measurement range | Accuracy | Response time | Typical gases |
|---|---|---|---|
| ppm → % | ±0.5–1 % | < 1 s (inline) | CH₄ · CO₂ · CO |
What gases can Beamonics analyzers measure?
Beamonics analyzers can detect key industrial gases, CH₄, NH₃, H₂S, HF, CO, CO₂, and HCl, using laser wavelengths tuned to each molecule’s absorption line. Each model targets specific applications: BeamSight for fast remote detection (CH₄, NH₃, HF), BeamStack for process integration (HF, CO₂, H₂S, HCl), BeamCell for laboratory analysis and calibration.
| Measurement range | Accuracy | Response time | Typical gases |
|---|---|---|---|
| ppb – % | ±0.5 – 1 % | < 1 – 3 s | HF · NH₃ · CH₄ · H₂S · CO₂ · HCl |
How accurate are Beamonics analyzers?
Beamonics analyzers typically achieve ±1 % accuracy under real-world conditions, using stable diode lasers and in-built reference calibration.
Example figures from datasheets:
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BeamSight BM-V-2: HF 0.05 ppm·m precision, CH₄ 15 ppm·m
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BeamStack BM-H-3: HF 0.01 ppm, CH₄ 0.2 ppm
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BeamCell BM-H-3: HF 0.05 ppm (extractive)
Temperature, pressure, and optical drift are auto-compensated to maintain consistent performance.
| Measurement range | Accuracy | Response time | Typical gases |
|---|---|---|---|
| ppb – % | ±0.5 – 1 % of reading | < 1 – 3 s | HF · CH₄ · NH₃ · H₂S |
How fast is the response time of a Beamonics TDLAS analyzer?
Our instruments measure in real time, with no T90-time. The BeamSight provides sub-second response since it measures directly in situ. Extractive systems like BeamStack or BeamCell add a short delay due to sample flow and conditioning. Residence time can be estimated from tubing volume and flow rate.
| Measurement range | Accuracy | Response time | Typical gases |
|---|---|---|---|
| ppm – % | ±1 % of reading | 0.5 – 3 s | NH₃ · HF · CH₄ |
