BS EN ISO 8311:2013 pdf free
BS EN ISO 8311:2013 pdf free.Refrigerated hydrocarbon and non-petroleum based liquefied gaseous fuels
The calibration of membrane tanks is basically the measurement of the tank length, width and height between known points. These measuring points are determined by setting out a number of horizontal,longitudinal and section planes.
These planes intersect to form lines along which the measurements of length, width and height shall be taken. The various planes shall be set out at intervals not greater than 5 m; the interval shall be adjusted so that the resulting measurements reflect any change of section and adequately describe any deformation. The points at which measurements are to be taken shall be determined by the calibrator but shall not be more than 5 m apart.
Having determined the measuring points, mark the lines which run on the tank inner walls. Mark the section and longitudinal lines on the top and bottom plates, horizontal and vertical lines on the fore and aft end walls and horizontal and vertical lines on the port and starboard end walls. When measurements are made by an EODR, coordinates of the planned measuring points may be stored in the instrument instead of actually marking the lines or points on the tank inner walls.
The EODR instrument shall be set up with the following steps.
a) The number and locations of the instrument stations shall be determined in order not to exceed incidence- angle limitations of equipment. If more than one station is necessary, survey traverse techniques should be used to move from one station to the other.
b) The instrument shall be set up with care, particularly in the horizontal and vertical axes and according to the procedure and instructions given by the manufacturer.
c) The instrument shall be set up so as to be stable and free from external vibrations. If necessary,the tank shell, in the vicinity of the instrument, shall be made firm and steady by placing heavy weights in the area. The legs of the tripod on which the instrument is mounted may be steadied using suitable devices to prevent slippage on the tank bottom.
d) The sighting lines from the instrument to the tank shell shall not be obstructed.
e) At least the minimum settling time recommended by the manufacturer should be allowed before the instrument is used.
f) If the distance-measurement part is separate, parallax adjustment should be made at the start. The distance optical beam and laser beams should be adjusted after temperature equilibrium, to ensure zero parallax, and then locked in position.BS EN ISO 8311 pdf free.