EI HM 2 : 2000

Foreword
Acknowledgements
1 Introduction and scope
2 Definitions
3 Safety
  3.1 General
  3.2 Lighting
  3.3 Tank ventilation
  3.4 Entry into tanks that have contained leaded fuels
  3.5 Personnel safety
4 Equipment
  4.1 Introduction
  4.2 General
  4.3 Dip-tapes, dip-weights and ullage-rules
  4.4 Steel strapping-tapes
  4.5 Spring balance
  4.6 'Littlejohn' grip
  4.7 Step-overs
  4.8 Tape positioners
5 Procedures to ensure accuracy
  5.1 General
  5.2 Measurements
  5.3 Tank deformation
  5.4 Tank abnormality
  5.5 Measurement obstructions
  5.6 Tank drawings
  5.7 Interruption of calibration
  5.8 Measurement units
6 IP Method 1 - Calibration by external measurement of
  circumference using strapping tape (strapping method)
  6.1 General
  6.2 Equipment
  6.3 Preparatory work
  6.4 Circumference measurement - strapping levels
  6.5 Strapping procedure
7 IP Method 2-1 - Calibration by internal measurement,
  diameter by direct measurement (internal diameter method)
  7.1 General
  7.2 Equipment
  7.3 Preparatory work
  7.4 Diameter measurements
8 Other measurements required for the strapping or
  internal diameter methods
  8.1 Plate thickness
  8.2 Paint thickness
  8.3 Course heights
  8.4 Datum points
  8.5 Deadwood
9 Tank bottom calibration
  9.1 General
  9.2 Liquid fill method
  9.3 Survey methods
  9.4 Tanks with profiled bottoms
10 Measurement of tilt
  10.1 General
  10.2 Methods of measurement
11 Calibration of floating roof tanks
  11.1 General
  11.2 Floating roof calibration
  11.3 Critical zone calibration
  11.4 Roof deadwood
12 Computation of tank calibration tables - open
   capacity calculations
  12.1 General
  12.2 Computation of open capacity - IP method 1
  - Strapping
  12.3 Computation of open capacity - IP method 2-1
  - Internal diameter measurement
13 Computation of tank calibration tables - IP methods
  1 and 2-1
  13.1 General
  13.2 Deadwood
  13.3 Tank bottoms
  13.4 Floating roof tanks - additional calculations
  13.5 Internal floating roof tanks
  13.6 Expansion due to hydrostatic pressure (liquid
  head effect)
ANNEXES
A Constants and conversion factors
  A.1 Constants
  A.2 Conversion factors
B Tank calibration data and calculation sheets
  B.1 Example of calculation of a capacity table for
  a tank calibrated by strapping method
  B.2 Example of calculation of a capacity table for
  a tank calibrated by the internal diameter method
C Recommendations for the checking and verification
  of tank calibrations and calibration tables
  C.1 Introduction
  C.2 Criteria factors
  C.3 Recalibration
  C.4 Recalculation due to operational changes
D IP method 2-2 - Calibration by internal measurement
  - Diameter by offset measurement (Internal offset method)
  D.1 Introduction
  D.2 Method
  D.3 Equipment
  D.4 Procedure
  D.5 Reference diameter measurement
  D.6 Measurement of offsets
  D.7 Determination of diameters above reference level
  D.8 Other measurements
  D.9 Computation of the calibration tables
E Derivation of the equations for correction of
  hydrostatic pressure effect
  E.1 General
  E.2 Correction for tank expansion at time of measurement
  E.3 Correction for tank expansion in service
F Expansion due to temperature
  F.1 General
  F.2 Preparation of tank calibration tables at any
  temperature of certification
  F.3 Calculation of capacities/oil quantities at
  temperatures other than the certification temperature of
  the calibration table
G Tank calibration record
  G.1 General
  G.2 Tank calibration record
H Bibliography

Details three calibration methods that have been drawn up to provide an accuracy consistent with the most stringent requirements and the procedures and equipment described represent the minimum requirements to achieve an acceptable level of measurement uncertainty. The three methods that are described are: calibration by strapping; calibration by direct measurement of the internal diameter of the tank using a tape, and; calibration by measurement of internal diameter using an offset measurement method.