Look beyond the automated test result

IEC 61010-2-081:2019 addresses the safety of automatic and semi-automatic laboratory equipment for analysis and other purposes. Examples include automated samplers, pipetting equipment and sample replication or amplification equipment. A system may automate the entire process or only part of the sample-handling, preparation or measurement sequence.

Edition 3 is used with IEC 61010-1:2010+A1:2016, the general requirements within the IEC 61010 safety framework. In vitro diagnostic equipment covered by IEC 61010-2-101 is excluded from Part 2-081. The intended use matters more than simply calling a product a laboratory analyser.

A stopped sequence is not necessarily safe access

Imagine that opening the cover makes a PLC display “cycle stopped”. The arm may still be slowing down, the needle may remain exposed, a heater may be hot and a fluid line may retain pressure. A status message alone does not prove that access is safe. Assess the protective arrangement against the hazards that remain when access becomes possible.

Useful design questions include: Which movement is inhibited? What happens if a cover sensor or its cable fails? Can the instrument restart unexpectedly after power returns? These are engineering questions, not a claim that Part 2-081 imposes an identical two-channel circuit or a particular performance level on every instrument.

Follow the hazards through the instrument

Electrical paths: Consider the supply circuits, accessible conductive parts, insulation and possible liquid ingress. The need for protective earthing depends on the equipment’s protection class. A 24 V drive or valve inside the instrument does not establish that every internal circuit operates at a safe extra-low voltage.

Moving parts: Sampling needles, pipetting arms and tube carriers can injure someone entering their working area. A sensor connected through an I/O module may provide ordinary process feedback. An inductive position sensor, however, is not by itself evidence that the complete protective function has been validated.

Temperature: A Pt100 or thermocouple can supply feedback to a heated compartment. PID control regulates the process temperature; protection against hazardous overheating must also be assessed. Choosing between RTDs and thermocouples helps establish measurement performance, but does not settle the entire thermal safety design.

Fluids and samples: Think about damaged tubing, leaking fittings, pressurised spray and contaminated waste. A normal reading from a pressure sensor does not demonstrate that every connection is leak-free. Chemical and biological hazards depend on the samples and reagents actually used.

Make connections and maintenance unambiguous

Where needed for safety, gas and liquid connections must identify the fluid, permitted pressure and applicable flow direction. Similar-looking tubes are not necessarily interchangeable. Choose cleaning agents for both their cleaning action and their compatibility with tubing, seals, surfaces and warning labels.

Before maintenance, follow the manufacturer’s procedure for isolating electrical energy, releasing pressure, allowing hot parts to cool and removing hazardous residues. A software stop is not electrical isolation. Distinguish operator maintenance from work reserved for service personnel; access restrictions and maintenance instructions must remain usable throughout the instrument’s life.

Equipment safety and analytical performance need separate evidence

IEC 61010-2-081 does not certify analytical accuracy or replace calibration. The analog measurement chain, analytical method and sample handling need their own checks. Assess electromagnetic interference using the applicable IEC 61326 EMC parts. A CE marking should likewise not be interpreted as a single test covering every aspect of safety and performance.