DIN 55473 Desiccant Unit Sizing Calculator
Size standard DIN / Mil-Spec desiccant units (U) for sealed barrier packaging. Enter your enclosure surface area, barrier film transmission rate (WVTR), and ocean transit duration to determine the pouch quantity you need.
DIN 55473 / MIL-D-3464E Sizing Model
Calculate exact DIN desiccant units (U) required for sealed moisture-barrier export packaging according to DIN 55474 standards.
Understanding DIN 55473 & DIN 55474 Sizing Standards
When exporting sensitive industrial machinery, pharmaceuticals, or electronics in sealed moisture-barrier bags (MIL-PRF-131 or heavy PE foil), calculating desiccant by guesswork leads to either cargo corrosion or unnecessary packaging cost.
1. Air Enclosure Moisture (V · b)
The moisture initially trapped inside the ambient air of the barrier envelope at the time of sealing. Standard warehouse air at 25°C and 60% RH holds approximately 14 to 18 g/m³ of water vapor.
2. Transmitted Moisture (A · e · W · t)
The moisture that permeates through the barrier film over time. Aluminum composite foil transmits <0.05 g/m²·d, while standard PE film allows 0.5 to 1.5 g/m²·d depending on thickness and oceanic temperature. Note: The route severity multiplier (e) applied in this calculator is our practical export logistics adjustment for high-temperature maritime transit, distinct from the standard DIN 55474 material ageing coefficient.
3. Unit Capacity Standard (a = 6.0g)
DIN 55473 defines 1 Desiccant Unit (1 U) as the quantity of desiccant that adsorbs at least 6.0 g of water vapour at 40% RH. DryGelWorld manufactures Type A silica gel sachets and bentonite clay pouches sized against that benchmark. This tool applies the arithmetic set out in that standard; it is not a certification, and DryGelWorld does not hold a DIN 55473 certification.
Frequently Asked Questions: DIN 55473 Sizing
Key standards, unit definitions, and engineering specifications for barrier export packaging.
What is a DIN 55473 Desiccant Unit (U)?
A DIN 55473 Desiccant Unit (often written as 'U' or 'T') is the quantity of desiccant that adsorbs at least 6.0 grams of water vapor at 20°C and 40% Relative Humidity (RH), and at least 3.0 grams of water vapor at 20°C and 20% RH. For standard Type A silica gel, one DIN unit corresponds to approximately 32 to 34 grams of active media.
What is the difference between DIN 55473 and MIL-D-3464E units?
Both DIN 55473 (German standard) and MIL-D-3464E (US Military standard) define a desiccant unit based on the exact same adsorption capacity: 6.0 grams of moisture at 40% RH and 3.0 grams at 20% RH. 1 DIN Unit is functionally equivalent to 1 Mil-Spec Unit.
How is the required desiccant quantity calculated for barrier packaging?
Under DIN 55474, the formula is U = (1/a) * (V * b + A * e * W * t), where V is internal air volume, A is packaging surface area, W is water vapor transmission rate (WVTR), t is transit time, e is the destination climate factor, and a is the standard 6.0g unit capacity.