GasClam 2 Instrument User Manual
Ion Science Ltd.
Unrivalled Gas Detect
ion.
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14
Typically, temperatures in a borehole will not go below 3°C and will not exceed 15°C however, this will depend on
installation. If the GasClam 2 is used above ground then temperatures can vary more widely.
The Ni-MH rechargeable battery on the GasClam 2 lasts approximately 670 samples (hourly sampling). To ensure
the GasClam 2 does not take more samples than the filters capacity use the table above to set the sample count
(see Software “Setup”), e.g. if the borehole is at 30°C set the s
ample number to less than 520.
It is unlikely that RH in a borehole will exceed 90% all the time and to help assess how to manage the filter after
the first installation there is an indicator system. The indicators work differently below 30°C and above 30°C (see
section “Servicing”).
Temperatures Below 0°C
If the temperature drops below 0°C and there is high humidity the valves in the GasClam 2 may freeze and prevent
correct sampling and a pump error will be flagged. This will not damage the GasClam 2; when temperature rises
above 0°C it will function correctly (see section “Fault Finding”).
Typically the GasClam 2 is installed in boreholes below the ground and the GasClam 2 will not go below 0°C due to
ground heat. If the GasClam 2 is installed above the ground, insulation or a heater will be needed to prevent
freezing. If you are unsure about your GasClam 2 installation contact your local supplier.
The Effects of Water on a GasClam 2
The GasClam 2 is designed to:
•
measure gas concentrations,
•
measure borehole and atmospheric pressure,
•
allow a venting pathway between the borehole and atmosphere,
•
the GasClam 2 software enables a selection of venting options.
To measure gas concentrations the gas must be dry and measurements of atmospheric pressure should not include
the pressure of overlying water. As the GasClam 2 can be in a position liable to flooding from above (flooded
Headworks) and below (borehole water level) it is necessary to:
•
carrying out simple preventive and remedial maintenance and
•
being aware of the limitations of data gathered under flood conditions.
How the GasClam 2 Prevents Water Entering From Below
To prevent water entering the GasClam 2 from below a water proximity sensor is situated below the gas inlet. If
water rises up the borehole and comes into contact with the proximity sensor the GasClam 2 will pause logging.
When water level drops GasClam 2 will resume logging after 1 hour.
To prevent water from reaching the gas inlet barb and flooding the GasClam 2, the Filter Cover creates an air
pocket at the base of the GasClam 2 (Always check to see if the cover is not damaged or cracked as this could then
let water in).
The air pocket should stop water from reaching the gas inlet for at least 7 days when the GasClam 2 is completely
submerged with 20 cm of water above its head. If the GasClam 2 is immersed for longer, the User must check to
ensure water has not reached the inlet barb before restarting the GasClam 2. If the User suspects that water may
have reached the gas inlet they must contact their local service centre.
NOTE
: The water proximity sensor works on the principle of conductivity and when water comes into contact
with the sensor it completes the circuit switching off the GasClam. If a non-conducting fluid, such as oil, is
