ISO 12917-2:2002 PDF

Overview

ISO 12917-2:2002 specifies the internal electro-optical distance-ranging (EODR) method for calibration of horizontal cylindrical tanks used for petroleum and liquid petroleum products. It applies to tanks with diameters greater than 2 m and covers internal measurement procedures, equipment requirements, data recording and the compilation of tank-capacity tables. The method is applicable to tanks inclined up to 10 % from horizontal (with a correction for measured tilt).

Key topics and technical requirements

• Measurement method: Internal electro-optical distance-ranging (EODR) using an electro-optical distance-ranging instrument to record slope distance, horizontal and vertical angles to target points.
• Equipment specifications:
  • Angle measurement: resolution/gradation ≤ 0.002 gon; repeatability ≤ ±0.005 gon.
  • Distance measurement: resolution ≤ ±1 mm; repeatability ≤ ±2 mm.
  • Low-power laser emitter compliant with IEC 60825-1 for target positioning.
  • Stadia bar (typically 2 m) with dimensional stability within ±0.02 mm.
  • Stable tripod and auxiliary steadying devices (e.g., magnetic bearers).
• Target point selection:
  • No target points within 300 mm of weld seams or stiffeners.
  • Cylindrical courses: minimum 16 points per course for tanks