ADM & Sub Aspida
User Manual
Int. Approved
Document ref: PSA-811-22
March 2020
Page 20 of 45
Copyright © 2017 Analox Ltd. All Rights Reserved.
Commercial in Confidence
6.9
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 6.18 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.
Summary of Contents for ADM Aspida
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