The Safety Management Group has published a safety alert from Sperian Instruments regarding the possible malfunctioning of BioSystems PhD5 portable gas detector. The notice states that
"There is a possibility that PhD5 instruments that have the Security Beep function enabled can stop actively detecting gas while continuing to show safe readings"
The notice further states that only a "handful" of detectors may be affected but it advises users to disable the security beep in the instrument as an immediate solution to the problem. It was not clear how disabling the security beep solved the problem, perhaps it is a bug in the instruments firmware. If the security beep is enabled, apparently some instruments stop actually measuring the gas, while showing safe readings! This is a dangerous failure and users should contact Sperian Instruments to update the firmware.
More details can be found on the Safety Management Group Website.
