---
title: Learning Path: New to Gas Analysis | Sarvesh
url: https://www.sarveshanalytics.com/learn/path-new-to-gas-analysis.html
description: A ten-lesson path from zero: what online gas analysis is, units, gas behaviour, accuracy, response time, technologies, sampling and calibration basics.
updated: 2026-11-03
source: html
---

Learn · Learning path

# New to gas analysis

Ten lessons, in the order that makes each one easier than it would be alone.

 10 lessons About 32 min For: Engineers, buyers and students meeting process gas analysis for the first time

## What you will be able to do

- Say what an online analyser measures and what it cannot
- Read ppm, percent and dew point without confusion
- Explain accuracy, drift and response time
- Name the main sensor technologies and when each fits
- Describe why sampling and calibration decide real-world results

## Follow these lessons in order

1. [  **What is online gas analysis? A plain introduction** Online gas analysis measures the composition of a process gas continuously, as it flows, and sends the result to a display, an alarm or a control system. The whole subject in one lesson.  Beginner*3 min*](https://www.sarveshanalytics.com/learn/what-is-online-gas-analysis.html)
2. [  **Online vs laboratory vs portable gas analysis** Use an online analyser when the answer is needed continuously to control or protect a process. Why plants measure online at all.  Beginner*3 min*](https://www.sarveshanalytics.com/learn/online-vs-laboratory-vs-portable-gas-analysis.html)
3. [  **How gases behave: pressure, temperature and partial pressure** In a gas mixture each component contributes a partial pressure equal to its fraction times the total pressure. The physics behind most surprises.  Beginner*3 min*](https://www.sarveshanalytics.com/learn/how-gases-behave-pressure-temperature-and-partial-pressure.html)
4. [  **ppm, percent and ppb explained for gas analysis** Percent, ppm and ppb are volume fractions: 1 % equals 10,000 ppm, and 1 ppm equals 1000 ppb. Units, so numbers mean the same to everyone.  Beginner*3 min*](https://www.sarveshanalytics.com/learn/ppm-percent-and-ppb-units-explained.html)
5. [  **Dry basis vs wet basis in gas measurement** A wet-basis reading counts water vapour as part of the gas; a dry-basis reading removes it. A hidden assumption in every reading.  Intermediate*3 min*](https://www.sarveshanalytics.com/learn/dry-basis-vs-wet-basis-gas-measurement.html)
6. [  **Accuracy, precision, repeatability and drift in gas analysers** Accuracy is how close a reading is to the true value; precision or repeatability is how closely repeated readings agree; drift is how the reading moves over time. What the specification promises.  Intermediate*3 min*](https://www.sarveshanalytics.com/learn/accuracy-precision-repeatability-and-drift.html)
7. [  **Response time, T90 and sample lag in gas analysis** T90 is the time an analyser takes to reach 90 % of a step change in concentration. Why a reading is late.  Intermediate*3 min*](https://www.sarveshanalytics.com/learn/response-time-t90-and-sample-lag.html)
8. [  **Gas analysis technologies compared: which sensor for which gas** Each gas analysis technology works only on gases with the right physical property: electrochemical and paramagnetic sensors for oxygen, zirconia for hot oxygen, NDIR for gases that absorb infrared (CO, CO2, methane), thermal conductivity for binary mixtures such as hydrogen in nitrogen, ceramic or chilled-mirror sensors for moisture. A map of the sensor world.  Beginner*3 min*](https://www.sarveshanalytics.com/learn/gas-analysis-technologies-compared.html)
9. [  **How to design a gas sample handling system** A good sample handling system delivers a representative, clean, dry sample at constant pressure and flow. Why the sample matters as much as the sensor.  Intermediate*4 min*](https://www.sarveshanalytics.com/learn/how-to-design-a-gas-sample-handling-system.html)
10. [  **How gas analyser calibration works: zero and span** Calibration compares the analyser's reading with a gas of known concentration and adjusts it to match. How a reading is kept true.  Beginner*4 min*](https://www.sarveshanalytics.com/learn/how-gas-analyser-calibration-works.html)

Stuck on a real problem while you learn? [Ask an engineer](https://www.sarveshanalytics.com/contact.html#enquiry). Every lesson is checked against the figures in our catalogues.