--- title: Gas Sampling and Conditioning: A Complete Guide url: https://www.sarveshanalytics.com/learn/track-sampling.html description: How to take a representative gas sample: sample point, tubing, filters, cooling, pressure and flow, hot dusty gas, cryogenic samples and troubleshooting. updated: 2026-11-03 source: html --- Learn ยท Track 3 of 8 # Sampling and conditioning Getting a representative, clean, dry sample to the analyser, which decides most field problems. 10 lessons About 33 min ## What this track covers Most analyser complaints are sample problems, not analyser problems. A perfect sensor reads a bad sample perfectly. This track follows the sample from the process to the sensor, in the order things happen. It also says clearly which samples an analyser cannot take, so that you find out on paper rather than at commissioning. ## Lessons, in order 1. [ **How to design a gas sample handling system** A good sample handling system delivers a representative, clean, dry sample at constant pressure and flow. Intermediate*4 min*](https://www.sarveshanalytics.com/learn/how-to-design-a-gas-sample-handling-system.html) 2. [ **Choosing the sample point for a gas analyser** Take the sample where the gas is well mixed, at process conditions you understand, upstream of any air leak, away from dead zones, and with a tapping that cannot fill with liquid or dust. Intermediate*4 min*](https://www.sarveshanalytics.com/learn/choosing-the-sample-point.html) 3. [ **Sample lines: materials, length, diameter and lag** Use stainless steel tube for trace oxygen, moisture and reactive gases, because plastic lets oxygen and water in and out. Intermediate*4 min*](https://www.sarveshanalytics.com/learn/sample-lines-materials-length-and-lag.html) 4. [ **Filters for gas analysers: dust, mist, membrane** Use filtration in stages: a coarse filter or probe filter near the tapping for bulk dust, a finer filter after the cooler, a coalescing filter to remove liquid mist and oil aerosol, and a membrane filter as a final guard. Intermediate*3 min*](https://www.sarveshanalytics.com/learn/filters-and-particulate-protection.html) 5. [ **Condensate, moisture and sample cooling for gas analysis** Wet samples must be cooled to a fixed, low dew point so that water leaves as condensate at a controlled place, not in the analyser. Intermediate*3 min*](https://www.sarveshanalytics.com/learn/condensate-moisture-and-sample-cooling.html) 6. [ **Sample pressure, flow and fast bypass loops** An analyser needs a steady sample at its specified pressure and flow. Intermediate*3 min*](https://www.sarveshanalytics.com/learn/sample-pressure-flow-and-bypass-loops.html) 7. [ **Probes and blowback for hot, dusty and tarry gas** Hot, dusty or tarry gas needs a probe that survives the temperature, a filter at the tip that keeps dust out, and a way to clear the filter, usually automatic blowback with clean air or gas. Intermediate*3 min*](https://www.sarveshanalytics.com/learn/hot-dusty-gas-probes-and-blowback.html) 8. [ **Sampling cryogenic and liquefied gases: vaporisers** A liquid sample must be vaporised completely before it reaches an analyser. Intermediate*3 min*](https://www.sarveshanalytics.com/learn/sampling-cryogenic-and-liquefied-gases.html) 9. [ **What samples an analyser cannot take: know the limits** Standard ACCURRA-S analysers expect a non-corrosive, non-toxic, non-flammable, non-condensing and dry sample, free of oil, at 2 to 10 psig and about 1 LPM, with dust below 3 micron. Intermediate*3 min*](https://www.sarveshanalytics.com/learn/what-samples-an-analyser-cannot-take.html) 10. [ **Sample system troubleshooting: symptoms to causes** Most analyser faults are sample system faults. Intermediate*3 min*](https://www.sarveshanalytics.com/learn/sample-system-troubleshooting.html) Next track: [Installation and integration](https://www.sarveshanalytics.com/learn/track-installation.html)