The Ministry of Consumer Affairs, Food & Public Distribution has published draft rules to amend the Legal Metrology (General) Rules, 2011, by inserting detailed metrological and technical requirements for Clinical Electrical Thermometers for Continuous Measurement. The proposed rules, named the Legal Metrology (General) Fourth Amendment Rules, 2025, are now open for comments from all stakeholders until August 30, 2025.
These draft rules are designed to ensure the accuracy, reliability, and safety of clinical thermometers used to continuously monitor human or animal body temperature, particularly during surgical procedures or intensive care. The rules apply to both battery- and mains-powered instruments and specify a minimum measuring range of 35.5 °C to 42.0 °C.
Key Provisions of the Draft Rules
Metrological Requirements
The standard unit of temperature must be degrees Celsius (°C).
Under reference conditions, the maximum permissible error for a complete thermometer is ±0.2 °C within the temperature range of 32.0 °C to 42.0 °C. Outside this range, the error may be twice this value.
The scale interval for digital displays shall not exceed 0.1 °C.
Technical Requirements
The rules specify that the probe must be disinfectable and designed to have sufficient electrical insulation. It must also be strong enough to withstand mechanical stresses from normal use.
The digital display of the temperature must be at least 4 mm in height and last for at least one second. The unit must also have a self-checking device to detect faulty operations. For battery-powered instruments, a clear low-voltage warning signal is mandatory.
The thermometer must maintain its accuracy after being subjected to various tests for thermal shock, humidity, electromagnetic interference, and electrostatic discharges.
Manufacturers are required to provide a comprehensive operating manual with information on installation, operation procedures, and precautions for disinfecting and cleaning the probe.
Public Consultation
All concerned stakeholders, including State Legal Metrology Departments, Voluntary Consumer Organisations (VCOs), industries, and industry associations, are invited to submit their comments and suggestions. The full text of the draft rules is available on the Department of Consumer Affairs’ website: www.consumeraffairs.nic.in.
Comments may be sent via email to dirwm-ca@nic.in and mk.naik72@gov.in by the deadline of August 30, 2025. This initiative is a step towards ensuring the accuracy and safety of a critical medical device, thereby protecting consumers and healthcare providers.