Description
Fitting a Desiccant Housing and Cartridge
When installing a gauge (vented) type LeveLine® logger with a vented cable, the free end of the cable must be positioned above the maximum expected water level. It is also essential to fit a desiccant housing and cartridge to the free end of the cable in order to prevent any moisture entering the cable or logger.
If you intend to use a telemetry device with a permanent connection to the cable, a Telemetry Cable Desiccant Housing (Part No. EX-TDH shown below) is required along with either a DC-50 or DC-100 Desiccant Cartridge.
The desiccant used within the Aquaread Desiccant Cartridges is a non-toxic, self-indicating synthetic amorphous silica designed to change colour as it absorbs moisture from orange to clear. Desiccant Cartridges are available in two sizes.
The choice of small (DC-50) or large (DC-100) Desiccant Cartridge is dependant upon the humidity at the deployment site and the expected maintenance frequency. If the deployment site is humid or the time between maintenance visits is expected to be long, the large (DC-100) Desiccant Cartridge is recommended.
The time taken for a fresh, dry Desiccant Cartridge to go from orange to clear (i.e. become fully saturated) is dependant upon site conditions. Regular maintenance checks should be made on the installation and the Desiccant Cartridge should be replaced or regenerated before it is completely saturated (clear).
To fit an Extension Cable Desiccant Housing (Part No. EX-DH), simply screw the free end of the Extension Cable onto the Housing as shown below. Once fitted, remove the cap from your chosen Desiccant Cartridge and screw the Cartridge into the Housing. Do not over-tighten the Cartridge.
The two vent holes located in the Desiccant Housing allow the pressure in the logger and cable to remain at ambient atmospheric. Air is allowed to vent slowly in and out of the assembly via an internal waterproof membrane. Any moisture that develops within the cable or logger due to condensation is absorbed by the Desiccant Cartridge. Do not block the vent holes or allow the housing to sit in water.
Regenerating Desiccant
When the desiccant in a Desiccant Cartridge has absorbed all the moisture it can and has changed from orange to clear, it can be regenerated and reused by a simple drying process.
Spread the desiccant crystals evenly on a suitable baking sheet and bake in an oven between 100°C and 200°C for around an hour or until the colour has changed from clear back to deep orange. After being allowed to cool, the crystals can be replaced in the Desiccant Cartridge and reused.