NF EN 12213 : 1999

National Foreword
Foreword
Introduction
1. Scope
2. Definitions
3. General conditions for all methods
4. Measuring the heat leak by the loss of product method
    4.1 General
    4.2 Test procedure
    4.3 Determination of the heat leak in units of energy
         per unit time
    4.4 Determination of the heat leak as a percentage of
         product lost per 24 h
5. Determination of the holding time (open system) in days
    from heat leak data
6. Holding times for closed systems
    6.1 Determination of the equilibrium holding time from
         heat leak data
    6.3 Static experimental holding time
7. Test report
8. Bibliography
Annex A (normative) Conversion of measured volumetric gaseous
flow to mass flow
Annex B (normative) Correction of measured mass flow rate with
regard to deviation from reference conditions
Annex C (normative) Equivalent loss determination, for product
other than the test product

A practical method to determine the heat leak performance of cryogenic vessels. Methods include measurement on open and closed systems. This standard does not specify neither the requirement levels for insulation performance nor when the methodology defined is applicable. These requirements may be defined in operational standards/regulations or in design.