Tuesday, March 19, 2019

Note on Use of the Supplementary Pro Check Feature in the Barryvox S

The supplementary “Pro Check” feature is an extension of the Barryvox S standard Group Check available only when the "Pro Search" function is activated.

Instructions for activating the Pro Check function are in the Barryvox S Extended Reference Guide (link).

This new feature is intended for guides and advanced users who want to see additional details of each transmitter within their group, as a tool to identify when the parameters of one transmitted signal might cause searching problems such as a higher incidence of signal overlap within the group. It is not a feature most rescuers should use every day and it is not considered a “critical check” like the standard Group Check feature. Specific guidance may be found on our previous blog post, HERE (link)

Recent reports indicate the Pro Check feature sometimes gives erroneous “out of tolerance” readings with some Backcountry Access (BCA) Avalanche Transceivers.

About The Supplementary “Pro Check" Feature in the Barryvox S

To best understand how to use Pro Check some background is helpful. All avalanche transceivers worldwide adhere to the same legal standard, or “norm”. This norm ensures compatibility between all transceivers worldwide, thus every transceiver is able to search for others and to be found by others, independently of the transceiver brand and model. Although all manufacturers operate under the same standard, there are still many older transceivers in use and every manufacturer applies slightly different transmit parameters within the legal framework.  Rescuers should be aware that each different signal within the norm parameters will always work with other transceivers. Some differences between individual signals, in particular in pulse rate, is even an advantage in multiple burial situations as it reduces the likelihood of persistent signal overlap. At the same time, each different signal can create different scenarios when in combination with various other beacons—many of the questions we get can be traced to such issues, so we want to provide people with a tool to see what may be driving the way their beacon interacts with other beacons.

The three parameters you'll see tested in Pro Check are defined by the international norm for avalanche transceivers as shown in Figure 1. 

Figure 1:  Transmitter parameters ETSI 300718