Sea-Bird Electronics SBE 38, Руководство пользователя

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Regeneration (drying) of Desiccant
Replacement desiccant bags are available from Sea-Bird:
•
PN 60039 is a metal can containing 25 1-gram desiccant bags and 1 humidity indicator card. The 1-gram bags
are used in our smaller diameter housings, such as the SBE 3 (
plus , F, and S), 4 (M and C), 5T and 5P,
37 (-SI, -SIP, -SM, -SMP, -IM, and –IMP), 38, 39, 39-IM, 43, 44, 45, 48, 49, and 50.
•
PN 31180 is a 1/3-ounce desiccant bag, used in our SBE 16 plus , 16 plus V2, 16 plus -IM, 16 plus -IM V2, 19 plus ,
19 plus V2, 21, and 52-MP.
•
PN 30051 is a 1-ounce desiccant bag. The 1-ounce bags are used in our larger diameter housings, such as the
SBE 9
plus , 16, 17 plus , 19, 25, 26, 26 plus , 32, 53 BPR, 54, 55, AFM, and PDIM.
However, if you run out of bags, you can regenerate your existing bags using the following procedure provided by the
manufacturer (Süd-Chemie Performance Packaging, a Division of United Catalysts, Inc.):
MIL-D-3464 Desiccant Regeneration Procedure
Regeneration of the United Desiccants’ Tyvek Desi Pak
®
or Sorb-It
®
bags or United Desiccants’
X-Crepe Desi Pak
®
or Sorb-It
®
bags can be accomplished by the following method:
1.
Arrange the bags on a wire tray in a single layer to allow for adequate air flow around the bags
during the drying process. The oven’s inside temperature should be room or ambient temperature
(25 – 29.4 °C [77 – 85 °F] ).
A convection, circulating, forced-air type oven is recommended for
this regeneration process. Seal failures may occur if any other type of heating unit or appliance
is used.
2. When placed in forced air, circulating air, or convection oven, allow a minimum of 3.8 to 5.1 cm
(1.5 to 2.0 inches) of air space between the top of the bags and the next metal tray above the bags.
If placed in a radiating exposed infrared-element type oven, shield the bags from direct exposure to the
heating element, giving the closest bags a minimum of 40.6 cm (16 inches) clearance from the heat
shield. Excessive surface film temperature due to infrared radiation will cause the Tyvek material to
melt and/or the seals to fail. Seal failure may also occur if the temperature is allowed to increase
rapidly. This is due to the fact that the water vapor is not given sufficient time to diffuse through the
Tyvek material, thus creating internal pressure within the bag, resulting in a seal rupture. Temperature
should not increase faster than 0.14 to 0.28 °C (0.25 to 0.50 °F) per minute.
3. Set the temperature of the oven to 118.3 °C (245 °F), and allow the bags of desiccant to reach
equilibrium temperature.
WARNING : Tyvek has a melt temperature of 121.1 – 126.7 °C
(250 – 260 °F) (Non MIL-D-3464E activation or reactivation of both silica gel and Bentonite clay can
be achieved at temperatures of 104.4 °C [220 °F]).
4. Desiccant bags should be allowed to remain in the oven at the assigned temperature for 24 hours.
At the end of the time period, the bags should be immediately removed and placed in a desiccator jar or
dry (0% relative humidity) airtight container for cooling. If this procedure is not followed precisely,
any water vapor driven off during reactivation may be re-adsorbed during cooling
and/or handling.
5. After the bags of desiccant have been allowed to cool in an airtight desiccator, they may be removed
and placed in either an appropriate type polyliner tightly sealed to prevent moisture adsorption, or a
container that prevents moisture from coming into contact with the regenerated desiccant.
NOTE: Use only a metal or glass container with a tight fitting metal or glass lid to store the regenerated desiccant. Keep
the container lid closed tightly to preserve adsorption properties of the desiccant.
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