Camera Dehumidifying Box Core Comparison: Condensation Chip Type vs Shape Memory Alloy Physical Moisture Absorption Card Durability Test

1. The physical conditions for the growth of lens fungus (Fungus) and the devastating damage to equipment

The interior of the optical lens uses natural animal and plant glue glued lenses, and the lens groups are sealed and dark:

1. The “golden breeding ground” for mold outbreaks:

• Ambient relative humidity (RH) is higher than 60% and the ambient temperature is between 20℃ and 35℃;
• Mold spores quickly germinate mycelium on the surface of the lens and secrete acidic hydrolase to corrode the advanced multi-layer coating of the lens;
• Even if the lens is sent for repair and cleaning later, the pits in the glass coating that are bitten by the acid can never be repaired, causing the lens to become white and foggy due to backlighting, sharply increasing glare, and halving the residual value of the used lens.

2. Optimal humidity balance point of moisture-proof box (40% - 50% RH):

• Do not over-dehumidify: If the relative humidity is lower than 35% for a long time, the damping grease in the lens zoom and focus ring will quickly dry up and evaporate, the leather of the fuselage will be degummed and cracked, and the shutter curtain rubber seal will harden and crack;
• Golden Protection Zone: Keep the humidity inside the box between 40% and 50% RH, which not only completely blocks the growth of mold, but also protects the elastic life of mechanical grease and rubber parts.

2. Technical route A: Semiconductor chip condensation (Peltier Effect Condensation)

At present, mainstream mid-to-high-end moisture-proof boxes generally use semiconductor refrigeration and dehumidification chip technology:

1. Working Mechanism:

• Utilizing the Peltier semiconductor refrigeration effect, the dehumidification chip is energized to generate a temperature difference, forming a micro "condensation dew point" at the refrigeration end of the box;
• The gaseous water molecules in the air in the box encounter the extremely cold condensation plate and quickly condense into liquid water droplets;
• The water droplets flow to the outside of the box along the micro-water pipe, and evaporate into the outside air using the outer heating end;

2. Advantages and Disadvantages Actual Measurement:

• Advantages: The dehumidification speed is extremely fast (after opening the door to pick up and place the lens, it can usually be reduced to the target humidity within 1 to 2 hours), the microcomputer humidity control is precise, and there is no mechanical noise;
• Fatal Disadvantage: Immediate failure after power outage: Once a household power outage occurs or the plug falls off, since there is no water storage and absorption medium, the humidity in the box will quickly rebound back to the ambient humidity level within a few hours; in addition, if the condensation dew pipe is blocked by scale, there may be a risk of internal water leakage.

3. Technical Route B: Shape Memory Alloy Molecular Sieve Moisture Absorbent Card (Shape Memory Alloy Molecular Sieve)

Polymer chemical moisture absorption solutions represented by veteran military moisture-proof boxes such as Collector and Wandefu:

1. Double-cycle physical moisture absorption cycle mechanism:

• Hygroscopic stage (no electricity passive moisture absorption): The box has a built-in polymer and highly active zeolite molecular sieve (Molecular Sieve), the internal valve is always open, and the hygroscopic agent wildly and passively swallows up the moisture molecules in the box. In this stage, no power is needed at all;
• Dehumidification stage (electrical heating regeneration): After absorbing moisture for several hours, the microcomputer controls the shape memory alloy spring to shrink due to heat, close the internal valve, open the external valve, and heat the molecular sieve through the built-in PTC heating ceramic to discharge the moisture out of the box in the form of steam (taking about 30-40 minutes);
• After the dehumidification is completed, the power is cut off, the memory alloy cools down and recovers, and the inner valve reopens to enter the next moisture absorption cycle.

2. Advantages and Disadvantages Actual Measurement:

• Absolute advantage: Super strong water retention during power outage: Even if there is a continuous power outage for 24 to 48 hours, the molecular sieve still has a strong ability to absorb and store water, and the humidity in the box will not surge instantly;
• Super long inorganic life: The chemical properties of polymer zeolite hygroscopic materials are extremely stable, no water droplets condense, and the life span is as long as 10 to 15 years or more;
• Disadvantages: The moisture absorption response is relatively slow, and it takes a longer period of time to return to 45% humidity after opening the door frequently.

4. Practical guide for purchasing and placing moisture-proof boxes to avoid pits

1. Capacity estimation multiplier rule (buy big, don’t buy small):

• Always choose a capacity that is 2 times the total volume of your current equipment!
• If a beginner who buys a 30L moisture-proof box with one camera and two lenses, the box will burst when he adds a telephoto lens, binoculars, handle or drone after half a year; it is recommended to choose at least 50L to 80L specifications at the beginning.

2. Physical placement environment of moisture-proof box:

• The exhaust hole on the back of the box must be at least 10 cm away from the wall, and it is strictly prohibited to place it against the wall;
• Keep away from windowsills and radiator vents exposed to direct sunlight to prevent the internal temperature and humidity sensor from being distorted and the internal glass from fogging due to severe local temperature differences in the box.