Analyzer Best Practices | Kaizen Controls And Automation

Best Practices for Continuous Online Analyzers: A Technical Guide for Reliable Process Measurement

In the process industries, gas analyzer sampling systems form the critical interface between the process stream and the analyzer. While analyzers are often engineered for robustness and high precision, the sampling system is frequently the weakest link—and the leading source of failures or inaccuracies.

This article explores the design principles, operational considerations, and key components of sampling systems. It explains why optimizing the sample path is essential for ensuring reliable, real-time analysis and minimizing costly maintenance or process disruptions.

1️⃣ Optimize System Compatibility

Analyzer performance begins with compatibility between your sampling system and the process fluid. Gases and liquids behave differently—and your sampling design must reflect this.

2️⃣ Sampling Point Location

Accurate data starts with smart sample extraction:

3️⃣ Keep Your Samples Timely

A delayed sample is often a distorted one. Aim for a total delay of less than one minute from sample extraction to analyzer measurement.
Common sources of delay include:

Even when each step seems efficient, small delays add up. For example, 49 seconds of transport time plus just 20 seconds of conditioning delay could already exceed your target of one minute.

4️⃣ Sample Conditioning: Cool or Dry?

Improper conditioning can damage analyzers or skew results:

Bühler pumps are designed for 24/7 continuous duty in harsh industrial environments. This makes them ideal for emission monitoring, combustion analysis, and process gas sampling, where uptime is critical.

5️⃣ Sample Transport: Designing Effective Sample Lines

The distance and pathway between sample tap and analyzer can impact accuracy:

Applied Analytics Analyzer with remote sampling. Eliminate long sample line runs!

6️⃣ Sample Conditioning at the Analyzer

This is the final checkpoint before analysis:

7️⃣ Pressure & Back Pressure Regulation

Maintaining proper pressure throughout the sampling system is crucial:

Alicat new line of I.S. multivariable forward pressure and back pressure controllers for Class 1 Div 1 Areas

8️⃣ Maintain Sample Composition

Even well-drawn, timely samples can be compromised before reaching the analyzer. Key risks include:

Buhler's Integrated Sample System with pump, chiller, and accessories

9️⃣ Supporting Utilities

Sampling systems rely on robust utilities:

🔟 Analyzer Location & Housing

Analyzer positioning plays a big role in uptime and safety:

Picture of a BARTEC Fully Integrated Shelter. They can do basic sunshades to entire climate control buildings.

🔧 Common Sampling System Failures

Sampling system reliability depends on good design and upkeep. Frequent issues include:

A well-designed sampling system ensures accurate, reliable, and timely analyzer measurements.

Need help designing your next sample system? Please contact Bobby Singh or Greg Brumfield! Want to eliminate a sample line? Check out our Close-Coupled Extractive Analyzers!

Temperature: Many chemical components are highly temperature-sensitive. Excess heat may boil a liquid sample; rapid cooling of a gas can result in condensation. Heated lines, coolers, and insulation help stabilize sample temperatures.​

Pressure: Pressure loss during transport can release dissolved gases or cause cavitation in liquids. Proper regulators and line sizing help minimize adverse effects.​

Flow: Slow-moving fluids cause more viscous drag, increasing solids buildup. Maintain higher flow rates before the analyzer to ensure clean lines and faster response.

​ ​ 2️⃣ Sampling Point Location ​ Accurate data starts with smart sample extraction: ​

Representative Sampling: Tap points should follow static mixers or be within recirculation loops.​

Avoid Dead Zones: Bypass stagnant areas to prevent sampling outdated or misleading material.​

Operator Safety: Choose accessible, low-risk locations.​

Process Integrity: Sampling should not disrupt flow or system balance.

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 3️⃣ Keep Your Samples Timely ​ A delayed sample is often a distorted one. Aim for a total delay of less than one minute from sample extraction to analyzer measurement.​ Common sources of delay include: ​

Pressure: Lower gas pressure at the tap point allows faster flow to the analyzer.

Probes: Appropriately sized probes reduce delay and ensure better sample representativeness.

Line Sizing: Oversized lines increase internal volume, which slows response time.

Dead Legs: Unpurged volumes allow mixing or diffusion of older sample material.

Analyzer Design: Manual analysis or slow cycle times contribute to cumulative delay.

Temperature Control: Use coolers or heaters to maintain a stable phase and prevent flashing.

Moisture Management: Only remove moisture if it’s not part of the measurement target.

Preserve Volatiles: Avoid loss of light components through excessive heating or long transport paths.

Liquid Sample Handling: Conditioning must prevent flashing, foaming, or thermal degradation.

Lag Time: Shorter, narrower tubing reduces time delays.

Tubing Material: Stainless steel is standard; PFA/PTFE is better for corrosives or adsorption-prone samples.

Insulation & Heating: Prevent condensation in gas lines.

Laminar Flow: Promotes consistent sample behavior and reduces buildup

​ ​ ​ ​ ​ ​ ​​ ​ Applied Analytics Analyzer with remote sampling. Eliminate long sample line runs! ​ ​ 6️⃣ Sample Conditioning at the Analyzer ​ This is the final checkpoint before analysis: ​

Filtration: Pre-filters and fine filters keep analyzers clean.

Coalescers/Demisters: Remove entrained liquids in gas samples.

Flow Control: Mass flow controllers and precision valves stabilize input.

Bypass & Purge Lines: Allow continuous flow, flushing, and maintenance without system shutdown.

​ 7️⃣ Pressure & Back Pressure Regulation ​ Maintaining proper pressure throughout the sampling system is crucial: ​

Inlet Pressure Regulators: Step down pressure before analysis.

Back Pressure Regulators: Especially important for liquids—maintain stable pressure to avoid flashing.

Avoid Pressure Drop: Prevent phase changes that skew results.

​ ​ ​ ​ ​ ​ ​​ Alicat new line of I.S. multivariable forward pressure and back pressure controllers for Class 1 Div 1 Areas 8️⃣ Maintain Sample Composition ​ Even well-drawn, timely samples can be compromised before reaching the analyzer. Key risks include: ​

Fractionation: Phase separation alters composition; maintain stable temperature and pressure.

Adsorption: Molecules may stick to tube walls or filter media—choose low-adsorption materials.

Contamination: Use process-appropriate filters and double-block-and-bleed stream switching valves to prevent cross-contamination and sample blending. Watch for dead legs that harbor old process fluid.

​ ​ ​ ​ ​ ​ ​ ​ Buhler's Integrated Sample System with pump, chiller, and accessories 9️⃣ Supporting Utilities ​ Sampling systems rely on robust utilities: ​

Instrument Air: For actuating valves and purging.

Electrical Supply: Powers heaters, pumps, and analyzers.

Cooling Water: Used in exchangers or chillers.

Drainage Management: Essential for safety and sample disposal.​

​ ​ 🔟 Analyzer Location & Housing ​ Analyzer positioning plays a big role in uptime and safety: ​

Close proximity to sample point minimizes lag and degradation

Use climate-controlled shelters or explosion-proof housings for outdoor or hazardous areas

Ensure ventilation, leak detection, and emergency relief systems

​ ​ ​ ​ ​ ​ ​ ​ ​Picture of a BARTEC Fully Integrated Shelter. They can do basic sunshades to entire climate control buildings. ​ ​ 🔧 Common Sampling System Failures ​ Sampling system reliability depends on good design and upkeep. Frequent issues include: ​

Design Oversights: Long lines, dead zones, or poor material choice

Maintenance Access: Inaccessible filters or valves increase downtime

Material Mismatches: Result in corrosion or unwanted reactions

Improper Validation: Lack of leak testing or response time checks

Temperature: Many chemical components are highly temperature-sensitive. Excess heat may boil a liquid sample; rapid cooling of a gas can result in condensation. Heated lines, coolers, and insulation help stabilize sample temperatures.

Pressure: Pressure loss during transport can release dissolved gases or cause cavitation in liquids. Proper regulators and line sizing help minimize adverse effects.

2️⃣ Sampling Point Location

Accurate data starts with smart sample extraction:

Representative Sampling: Tap points should follow static mixers or be within recirculation loops.

Avoid Dead Zones: Bypass stagnant areas to prevent sampling outdated or misleading material.

Operator Safety: Choose accessible, low-risk locations.

3️⃣ Keep Your Samples Timely

A delayed sample is often a distorted one. Aim for a total delay of less than one minute from sample extraction to analyzer measurement.
Common sources of delay include:

Applied Analytics Analyzer with remote sampling. Eliminate long sample line runs!

6️⃣ Sample Conditioning at the Analyzer

This is the final checkpoint before analysis:

7️⃣ Pressure & Back Pressure Regulation

Maintaining proper pressure throughout the sampling system is crucial:

Alicat new line of I.S. multivariable forward pressure and back pressure controllers for Class 1 Div 1 Areas

8️⃣ Maintain Sample Composition

Even well-drawn, timely samples can be compromised before reaching the analyzer. Key risks include:

Buhler's Integrated Sample System with pump, chiller, and accessories

9️⃣ Supporting Utilities

Sampling systems rely on robust utilities:

Drainage Management: Essential for safety and sample disposal.

🔟 Analyzer Location & Housing

Analyzer positioning plays a big role in uptime and safety:

Picture of a BARTEC Fully Integrated Shelter. They can do basic sunshades to entire climate control buildings.

🔧 Common Sampling System Failures

Sampling system reliability depends on good design and upkeep. Frequent issues include: