What is the H2S gas analyser used for?
The H2S gas analyser is designed to continuously measure hydrogen sulfide concentrations in gas streams. It is commonly used in natural gas processing, pipelines, biogas facilities, fuel gas monitoring, and wellhead applications.
How does the gas analyser measure H2S?
The analyser uses a lead acetate sensing tape. When H2S contacts the tape, a chemical reaction darkens the tape. An optical sensor measures the colour change and converts it into an H2S concentration reading. This method provides a linear and interference-resistant measurement.
What measurement ranges are available for the H2S gas analyser?
The analyser can measure H2S gas from very low ppb levels from 0% to 0.02% or 0-200ppm level. With optional dilution systems, it can measure much higher concentrations, including percentage levels of H2S.
How often should the H2S gas analyser sensing tape be replaced?
Tape replacement depends on H2S concentration, analyser cycle frequency, and tape consumption. Operators should regularly inspect tape supply and replace it before it runs out. Low-tape alarms may be available depending on configuration.
How frequently should H2S gas analyser maintenance be performed?
Routine inspections are recommended at least every three months while the maintenance process should include checking tape condition, filters, tubing, flowmeters, and sample conditioning components.
Does the H2S gas analyser require frequent calibration?
Under normal operating conditions, frequent recalibration is generally not required if the analyser is clean and functioning correctly. However, periodic verification with calibration gas is recommended as part of a preventive maintenance program.
What causes inaccurate or unstable readings of the H2S gas analyser?
Common causes include includes contaminated sample filters, moisture or liquid carryover in the sample system, damaged or improperly installed sensing tape, flow issues in the sample conditioning system and dirty optical components. Regular maintenance helps prevent these issues.
Can the H2S gas Analyser measure total sulfur?
Yes. Certain configurations can be equipped with a hydrogen reaction furnace to convert sulfur compounds into H2S, allowing total sulfur measurement.
Why is sample conditioning important for H2S gas analyser?
Proper sample conditioning removes liquids and particulates before they reach the analyser. This protects the sensing tape, improves measurement accuracy, and extends analyser life.
What environmental conditions can the H2S gas analyser operate in?
Standard operating temperature is typically 0°C to 50°C (32°F to 122°F).
How do I know when the H2S gas analyser sensing tape is low?
Many installations include a low-tape monitoring feature. If not equipped, operators should visually inspect tape supply during routine maintenance checks.
What are the most common consumable parts for the H2S gas analyser?
The most frequently replaced items are the H2S sensing tape, sample conditioning filters, humidifier components (if installed) and sample tubing affected by contamination. Regular replacement of these components helps maintain the analyser performance.
What is the maximum H2S gas analyser concentration and accuracy?
The maximum H2S concentration is 30% (300,000 ppm) while the accuracy is ±1.5% of full scale for the standard range and ±2.5% of full scale for the high range.
Where are online H2S gas analysers commonly installed?
Common H2S gas analysers installation points include wellheads, gas gathering systems, gas processing plants, pipeline custody transfer stations, fuel gas systems, refineries, biogas plants and sulfur recovery units
Why is H2S measurement important?
H2S is toxic, corrosive and can negatively affect product quality. Monitoring H2S gas helps protect personnel, prevent equipment damage, meet pipeline specifications and ensure process efficiency.
What analyser technologies are used to measure H2S online?
Common technologies include lead acetate tape analysers, tunable diode laser (TDL) analysers, UV fluorescence analysers, electrochemical sensors and tunable filter spectroscopy analysers. The best technology depends on concentration range, accuracy requirements and application conditions.
What makes ppb and ppm different?
Ppm is parts per million, and ppb is parts per billion. 1 ppm equals 1,000 ppb. Pipeline and environmental applications often require measurements at very low ppb levels.
Can an online H2S analyser replace laboratory testing?
Online analysers provide continuous real-time measurements, while laboratory testing provides periodic verification. Many facilities use both methods to ensure data accuracy and compliance.
What are the benefits of continuous H2S gas monitoring?
Continuous monitoring provides real-time process visibility, faster response to upsets, improved safety, reduced corrosion risk, better product quality control, regulatory compliance and lower operating costs through early problem detection
Why might analyser readings differ from laboratory results?
Differences can occur because samples were taken at different times, process conditions changed, sampling methods differed, laboratory and analyser measurement uncertainties vary and sample handling affected H2S concentration
