Overview
ISO 23346:2020 specifies terms, definitions and a general signal receiving measurement method for radio-controlled clocks. It applies to analog, liquid-crystal (LCD) and LED-display radio-controlled clocks, and can also be used as a reference by radio-controlled clock movements. The standard promotes consistent testing, objective performance verification and improved interoperability in international trade.
Key Topics
- Scope and definitions: establishes clear terminology for radio-controlled clock testing, including "radio-controlled clock", "standard time signal" and "receiving state".
- Test conditions: specifies environmental requirements such as ambient temperature (18 °C to 25 °C), temperature stability (±2 °C during the test) and relative humidity (30 % to 70 %).
- Power and pre-running: samples must be powered at nominal operating voltage and pre-run in the specified environment for the period defined by the product.
- Apparatus and equipment: identifies required instruments and their performance (for example, a field-strength meter with 1 dBµV/m resolution) and the use of a shielded room with appropriate shielding effectiveness.
- Test preparation and procedure: describes positioning of the standard time signal transmitter outside the shielded room, placing the antenna and the test sample inside, preheating the transmitter (minimum 30 minutes), and verifying signal strength at the test position before executing the receiving test.
Applications
This standard is directly useful for:
- Manufacturers of radio-controlled clocks and movements who need a repeatable method to verify receiving sensitivity and performance.
- Test laboratories and quality assurance teams that perform acceptance, compliance and production testing in controlled environments.
- Product designers and RF engineers validating antenna placement, immunity to background noise and signal reception behavior.
- Regulatory and procurement bodies requiring standardized test methods to compare products and support market access.
Practical benefits include reproducible test results, reduced disputes in international trade, and clearer documentation for product conformity and technical claims.
Related Standards
- Annex A of ISO 23346:2020 lists major low-frequency time-code transmitters worldwide (examples include DCF77, WWVB, MSF, JJY, ALS162 and BPC).
- Users should consult national time-service documentation for transmitter characteristics and any country-specific requirements.
Keywords: radio-controlled clocks, signal receiving measurement, test procedure, field-strength meter, shielded room, ISO 23346:2020.