Hollis Explorer User Manual - page 52
44 |
CDM (CANISTER DURATION METER)
The EXPLORER Canister Duration Meter (CDM) is comprised of three main
parts:
1. A patented, absorbent temperature profile duration meter.
2. A Nitrox Injection Meter (based on CE tested durations).
3. An optional gaseous CO
2
sensor accessory.
The CDM combines information from these three features to determine the
appropriate state of the scrubber. The STATUS combines and displays this
information as ‘Filter minutes.’ The Nitrox Injection Meter minutes are reset
when the absorbent is replaced and confirmed in the Pre-Dive Sequence.
The duration of the Scrubber depends mainly on the amount of CO
2
being
produced by the diver and the depth of the dive. The readings from all
of these devices together can be used to report a high confidence status
regarding the state of the Scrubber. However, user experience and train-
ing should also be used to determine the validity of the readings given.
Scrubbers are a key element of a rebreather. Great care should be taken
when determining if a dive can be safely performed with the scrubber in its
current state. Flooding, extended storage between uses, improper assem-
bly, and improper packing can all contribute to the canister duration meter
reporting false readings. Use great care in assembling the Explorer and in
completing pre-breathe checks on the breathing loop. The CDM is a useful
feature as an aid to predicting absorbent duration.
! WARNING: NEVER dive a partially used Scrubber beyond 24 hours
of its initial packing or opening irrespective of the CDM meter read-
ing. This includes partially used scrubbers that have been stored in
a sealed loop or container.
TPM (TEMPERATURE PROFILE MONITOR)
This meter relies upon the heat producing reaction of the CO
2
absorbent.
Utilizing multiple temperature sensors, the system detects a complex reac-
tion heat wave front through the absorbent as it is being used.
!
DANGER: The TPM will not detect breakthrough conditions of
a poorly packed Scrubber or failing seal. Therefore Pre-breathe
checks must always be carried out to ensure CO
2
is being absorbed
correctly by the scrubber.
The TPM contains 5 temperature sensors arranged longitudinally through
the canister absorption path. The readings from these 5 temperature
sensors are logged and analyzed by the system. The following describes