ADM, HBOT & Sub Aspida
User Manual
Int. Approved
Document ref: PSA-811-14
June 2017
Page 18 of 43
Copyright © 2017 Analox Ltd. All Rights Reserved.
Commercial in Confidence
5.9
Gas alarms
The Analox
Aspida
has a range of configurable alarms to warn the user of potentially dangerous
atmospheres. For each gas sensor fitted to the device, up to 3 configurable alarms are available. In the
case of carbon dioxide, an extra time weighted average (TWA) alarm is provided. See section 5.17 for
more details.
In the case of an alarm condition being detected, the horn will activate giving an audible warning to the
user. At the same time, the red alarm indicators will flash.
The device also has a vibrating alert to accompany gas alarms. When an alarm is triggered the unit will
vibrate (vibration limited to 10 seconds when man down detection is enabled). The unit will not vibrate
whilst connected to USB or the charger.
A gas alarm condition will also be shown on the display, giving a clear indication of the gas that has
triggered the alarm. In the case of an alarm, the gas warning symbol
will appear below the gas
reading which will be surrounded by a flashing border, as shown below.
Figure 5 - The main gas display showing that carbon dioxide levels have triggered an alarm
Each alarm is configurable as either high-going or low-going. In the case of a high going alarm, if the
gas value exceeds the configurable set-point, the alarm will be activated. The 3 gas alarms are also
ranked in order of priority, so that if a more dangerous level of gas is detected, the user is notified.
Example
Two low going alarms are normally configured for detection of low oxygen levels.
•
Priority 1 alarm is configured as a low going alarm with a set-point of 18.0% or 180mBar.
•
Priority 2 alarm is configured as a low going alarm with a set-point of 19.5% or 195mBar.
If using this setup the detected level of oxygen falls below 19.5%, priority 2 alarm will be activated.
The red indicators, vibration and horn will all activate, pulsing at a moderate rate, and a visual
warning will be given on screen. The oxygen value will be highlighted and the gas warning symbol
shown below the reading.
If the detected oxygen level falls further so that it is below 18.0%, priority 1 alarm will be activated.
This alarm is of a higher priority than the priority 2 alarm so the urgency of the alarm will be
increased. The indicators, vibration and horn will begin to pulse more rapidly to indicate that the
severity of the alarm has increased.
There is also normally a priority 3 alarm is configured as a high going oxygen alarm with a set-point of
23.0% or 230mBar
