Trolex XD1+ Alarms

Modified on Wed, 31 Jan at 1:48 PM

The Trolex XD1+ uses 2 LED indicators alongside audio sequences to alert users to an alarm threshold being breached for STEL and TWA.

STEL - Short-term exposure limit alarm (Indicator 1)

- The XD1+ will flash the amber STEL indicator alongside an audible alarm (2 beeps per second).

- The XD1+ is factory programmed with the following default STEL threshold:

- 1,000 μm/m3 over 15 minutes

- The XD1+ uses the following calculation for the monitoring of STEL threshold breach (STEL time in minutes):

TWA - Time-Weighted Average alarm (Indicator 2)
- The XD1+ will flash the red TWA indicator alongside an audible alarm (3 beeps per second).

- In the event that both alarms are triggered simultaneously, the TWA alarm will take priority.

- The XD1+ is factory programmed with the following default TWA threshold:

- 1,000 μm/m3 over 8 hours

- The XD1+ uses the following calculation for the monitoring of TWA threshold breach (TWA time in minutes):

The default threshold limits have been defined based on a quarter of the permissible limit for most respirable dusts as outlined in the EH40/2005 guidelines.

Advice outlined in EH40/2005 states that where no specific short-term exposure limit is listed, a figure three times that of long-term exposure limit should be used. However, always refer to local guidelines and legislation to ensure that alarm warning thresholds are set at appropriate and permissible values for the intended operating environment.

Note: The XD1+ is a personal safety device and it is the operator’s responsibility to respond accordingly to any warnings, alarms or alerts in accordance with site regulations and instructions. Follow all warnings and instructions marked on the instrument.