IEC 60601-1 Annex G.7 Flammable Gas Mixing Test Apparatus Medical Electrical Equipment

IEC 60601-1 Annex G.7 Flammable Gas Mixing Test Apparatus Medical Electrical Equipment

Product Overview:

The Flammable Gas Mixing Test Apparatus is designed to evaluate the explosion and ignition risks of medical electrical (ME) equipment operating in environments where flammable anesthetic gases are mixed with oxygen or nitrous oxide. The system simulates real operating conditions to verify whether sparks generated by heated ME equipment circuits can ignite flammable gas mixtures, ensuring compliance with international medical safety standards.

Applicable Standards:

GB 9706.1-2020 Medical Electrical Equipment – Part 1: General Requirements for Basic Safety and Essential Performance, Annex G.7

IEC 60601-1:2012 Medical Electrical Equipment – Part 1: General Requirements for Basic Safety and Essential Performance, Annex G.7

Test Samples:

ME equipment, components, and elements that heat flammable anesthetic gases mixed with oxygen or nitrous oxide.

Test Purpose:

This apparatus is used to assess whether sparks generated by the heating circuits of ME equipment can ignite flammable anesthetic gases when such gases or flammable agents are used for anesthesia, disinfection, or skin cleaning and are mixed with air, oxygen, or nitrous oxide. The test verifies the potential risk of ignition or explosion under specified conditions.

Test Principle:

A motor drives a shaft equipped with a tungsten wire disc rotating at 80 r/min. Electrical sparks are generated through the opening and closing of the test circuit between the tungsten wire and a cadmium disc. The sparks are used to ignite the flammable anesthetic gas introduced into the ignition chamber, thereby validating the safety of the tested electrical circuit when operating in flammable gas environments.

Equipment Structure:

The test apparatus consists of an ignition chamber and a contact mechanism:

Ignition chamber volume: ≥ 250 cm³, filled with specified gas or gas mixtures.

Contact mechanism: composed of one disc with two slots and another disc fitted with four tungsten wires (Ø 0.2 mm).

The second disc slides on the first disc, with a free tungsten wire length of 11 mm.

The shaft connected to the tungsten wire disc rotates at 80 r/min.

The shaft connected to the radial disc rotates in the opposite direction.

Speed ratio between the tungsten wire shaft and the opposing shaft: 50 : 12.

Overall dimensions: approx. 800 × 600 × 1500 mm (W × H × D)
Net weight: approx. 150 kg

Operating Environment:

Power supply: AC 220 V ±10%, 50–60 Hz

Rated power: 0.3 kW

Technical Parameters: