Overview
IEC TR 61831:2011 - On-line analyser systems - Guide to design and installation is an IEC Technical Report that provides guidance for specifying, designing and installing complete on-line analyser systems from the process sample point to the final output for display or control. This second edition (2011) updates references, aligns the document with current practices and regulations, and incorporates new technologies where applicable. It is intended as a practical guide for both system suppliers and users.
Key topics and technical requirements
The report covers the full analyser-system lifecycle and includes technical guidance on:
- Sampling systems and probes - sample point location, fast circulating (fast loop) and by‑pass systems, multi‑stream sampling, probe design and material selection.
- Housings and enclosures - analyser cases, cabinets, shelters and houses; construction, mounting and ventilation options (natural and forced).
- Ventilation and environmental control - ventilation sizing, intake and fan requirements, heating, ventilation failure logic and safety trip recommendations.
- Health, safety and environmental considerations - explosion/fire prevention, toxic/asphyxiant and radiation hazards, manual shutdown and safety facilities.
- Communications and signal handling - signal transmission, cabling, alarms, safety considerations and use of analyser outputs for control.
- Calibration and verification - calibration facilities and automatic calibration, plus example verification/calibration sequences.
- Reliability, design and centralization considerations - guidance on system architecture and maintenance access.
- Supporting calculations and schematics - annexes provide sample system calculations, natural and forced ventilation calculations, sample probe design examples, and typical system schematics.
Practical applications and users
IEC TR 61831:2011 is directly applicable to organizations involved with process analysers in industries such as oil & gas, petrochemical, chemical manufacturing, power generation and water/wastewater treatment. Typical users include:
- Process engineers and instrumentation specialists specifying analyser systems
- OEMs and system integrators designing analyser skids and shelters
- Maintenance and reliability engineers planning sampling and calibration strategies
- Safety and HSE personnel assessing risks associated with analyser installations
Why use this guide
- Ensures consistent, safe installation practices from sample point to control output
- Helps reduce measurement errors due to poor sampling, enclosure or ventilation design
- Provides practical examples, calculations and verification workflows to support commissioning and routine operation
Related standards
IEC TR 61831 is complementary to other IEC/ISO standards and industry guidance on electrical area classification, explosion protection, process instrumentation and industrial communications. Users should apply relevant national and industry regulations when implementing recommendations from this TR.