ISO 3405 pdf download Petroleum products — Determination of distillation characteristics at atmospheric pressure
5.4 Metal shield or enclosure for flask (manual apparatus only)
Shields shall be provided to protect the operator from damage to the unit during operation, and to protect thedistillation flask from draughts. These shall allow easy access to the distillation setup during operation, and beprovided with at least one window for observing the dry point at the end of the distillation.
NOTE1 A typical shield for a unitftted with a gas burner would be 400 mm high,280 mm long and 200 mm wde,made of sheet metal approximately 0,8 mm in thickness (see Figure 1).
NOTE2 A typical shield for a uni ftted with an electic heater would be 440 mm high, 200 mm long and 200 mm wide,made of sheet metal approximately 0,8 mm in thickness (see Figure 2).
5.5.1 Gas burner (see Figure 1), capable of bringing over the first drop from a cold start within the timespecified, and continuing the distilation at the specified rate. A sensitive regulating valve and gas pressuregovernor to give complete control of heating shall be provided.
5.5.2 Electric heater (see Figure 2), of low heat retention and adjustable from o w to 1 000 w.
5.6.1Type 1, for use with gas burner (see Figure 1).Either a ring support of the ordinary laboratory type,100 mm or larger in diameter, supported on a stand inside the shield, or a platform adjustable from the outsideof the shield shall be used.
The flask support board shall be constructed of ceramic or other heat-resistant material， 3 mm to 6 mm inthickness, and shall have a central opening conforming to the dimensions given in Table 2.The flask supportboard shall be of sufficient dimension to ensure that thermal heat to the flask only comes from the centralopening and that extraneous heat to the flask other than through the central opening is minimized.The flask-support board may be moved slightly in accordance with the directions for positioning the distillation flask sothat direct heat is applied to the flask only through the opening in this board. The position of the flask is set byadjusting the length of the side arm inserted into the condenser.
5.6.2Type 2, for use with an electric heater (see Figure 2). The flask support is a platform on top of theelectric heater，adjustable from the outside of the shield. The flask support board described in 5.6.1 ismounted on this support. Provision shall be made for moving the upper (flask-support) board slightly in thehorizontal plane to ensure that direct heat is applied only through the specified opening in this board. Theflask-support assembly shall be able to move vertically to ensure contact of the flask-support board with thebottom of the distllation flask during the distllation,and to allow for easy mounting and removal of thedistillation flask from the unit.
5.7.1 Receiving cylinder, of 100 ml capacity, generally in accordance with ISO 4788. It shall be graduatedat intervals of 1 ml beginning at least at the 5 ml mark and have a graduation at the 100 ml mark.The shapeof the base shall be such that the receiver does not topple when placed empty on a surface inclined at anangle of 13° to the horizontal.Construction details and tolerances for the graduated cylinder are shown inFigure 5.
For automated apparatus, the cylinder shall conform to the physical specifications described in this subclause,with the exception of all graduations but that at 100 ml.Receiving cylinders for use in automated units mayalso have a metal base.
lf required, the receiving cylinder shall be immersed to above the 100 ml graduation line in a cooling liquidcontained in a cooling bath,such as a tall-form beaker of clear glass or transparent plastic, or placed in athermostatically controlled air-circulation chamber.
5.7.2Residue cylinder, of 5 ml capacity, generally in accordance with ISO 4788.