NMI WebTimer

Laboratories looking to verify stopwatches and timers have been looking for an alternative source of traceable time since the shutdown of the Talking Clock in 2019. NATA guidance recommends verifying timers and stopwatches every six months, and suggests using a GPS/GNSS-directed device as a reference time source. However, setting up and using such a source of time typically requires specialist expertise and can be costly.

The Time and Frequency Standards team at the National Measurement Institute (NMI) has now developed the WebTimer, a simple and convenient service which can be used to make time interval measurements that are traceable to the Australian primary standard for time. The browser-based service provides a measurement of the time interval between two clicks of a button on a user’s computer (including mobile devices).

The service calculates and reports the measurement uncertainties on-screen. Users are able to print and save a report of their time-interval measurement that documents uncertainties and traceability to UTC(AUS), which serves as Australia’s primary standard for the SI base unit of time (the second) as well as Australia’s legal reference for time-of-day.

NMI already provides a means of realising traceable time interval measurements through its Network Time Protocol servers, but there are specific network and computer configuration requirements that may not be possible for some users. The user must also make the necessary calculations of time interval and its uncertainty. By being browser-based, the WebTimer is easily accessed from most computer and mobile platforms. The calculations of time interval and uncertainty are built in, thus simplifying the process of verifying timers and stop watches.

Access is via an annual subscription. Depending on uptake and client needs, NMI plans to roll out more WebTimer servers for increased accuracy for users across the country.