© 2019 Department of Petroleum Resources. All rights reserved Department of Petroleum Resources (DPR) PROCEDURE GUIDE

Page 77 of 114

76 | P a g e

compartment shall be noted and recorded. A capacity chart of the tank car shall then
be drawn up containing the calibrated capacities of each of the compartments.
2.8.7.5 Water weighing Procedures: A weighing device which has been certified for accuracy
by a body or Agency recognized by the Department of Petroleum Resources shall be
used for this exercise.
2.8.7.6 The net weight of water in each compartment of the tank car shall be obtained in
turn and in accordance with the procedure outlined in the referenced standards.
Based on this measurement, a calibrated capacity chart of each of the cargo
compartments for the whole tank car shall be prepared.
2.8.8 Presentation of Results
2.8.8.1 A capacity chart shall be drawn up as described in the foregoing and it shall contain
the ambient conditions during calibration, the references temperature of the stated
capacities with each compartment properly identified. The chart shall also contain
information on the certifying body for the primary volume measure or the weighing
scale with a photocopy of the certificate of accuracy of the primary volume
measurement available for inspection on request.
2.8.8.2 The chart shall show the capacity of each compartment according to incremental
depth. The date of calibration, description of the tanker trailer and the name of the
calibrating company shall be conspicuously displayed on the chart. In cases where
calibration is by water weighing, Table Viii of API 2554 shall be used to establish the
appropriate correction factor for the temperature effect on relative density.

2.9 Field-Standard Test Measure
2.9.1 Principle
The Test Measure so calibrated shall be the basis for calibrating all Proving Systems. The
Field-Standard Test Measure is a vessel fabricated to meet specific design criteria and
calibrated by an accredited international agent of a recognized standardization body.
The Field-Standard Test Measure shall be calibrated by a competent Laboratory that can
provide traceability of its equipment to the US National Bureau of Standards or any other
similar internationally recognized body.
2.9.2 Frequency of Calibration
The Field –Standard Test Measure shall be calibrated every three years and shall be
automatically rendered invalid by damage or dent to the body.

2.9.3 Calibration Procedure
2.9.3.1 Field –Standard Test Measure shall be calibrated by the accredited laboratory or
agency in accordance with the provisions of API Manual of Petroleum Measurement
Standard Chapter 4.7.
2.9.3.2 Calibration shall be made using water as calibration medium. Certified laboratory
graduates may be used to measure, partial volumes of a test measure. Actual
capacity of the test measure shall be used as Official capacity rather than the nominal
capacity of the measure. Calibrations shall be maintained at +0.02 percent minimum.