IEC 60705 pdf download – Household microwave ovens – Methods for measuring performance

IEC 60705 pdf download – Household microwave ovens – Methods for measuring performance
7.2.3Usable width
The usable width is the maximum length of a cylinder with a diameter of 200 mm reachinghorizontally from the left-hand side wall to the right-hand side wall of the cavity.
In the event that either the height or the depth of the cavity is less than 250 mm, the diameterof the cylinder to be measured shall be reduced to 120 mm.
NOTEThe centre of the side wall of the cavity is defined by the middle of the usable depth and the middle of theusable height.
7.2.4Usable depth
The usable depth is the maximum length of a cylinder with a diameter of 200 mm reachinghorizontally from the centre of the rear wall to the inner face of the closed door.
ln the event that either the width or the height of the cavity is less than 250 mm, the diameterof the cylinder to be measured shall be reduced to 120 mm.
For measuring the usable depth, the gauge is placed on a support in such a way that the axislies horizontally in the centre of the cavity, the axis being extended slightly over the expectedusable depth.The door is closed carefully so that the gauge is compressed to give the usabledepth.
NOTE The centre of the rear wall of the cavity is defined by the middle of the usable height and the middle of theusable width.
7.2.5Reciprocating tray
lf there is a reciprocating tray, the extent of movement of the tray is measured and subtractedfrom the usable dimension in the direction of reciprocation as measured above.
7.2.6Usable volume
The usable volume is calculated from these dimensions and is given in litres rounded to thenext full litre.
lf the appliance has a turntable，the base area for the usable volume is determined by thecircular area formed by twice the minimum distance between the axis of rotation of theturntable and the nearest wall or door multiplied with the usable height.
lf it is permissible to operate the appliance with the cavity divided into two parts by the use ofcomponents supplied with the appliance,the volume of each part shall be determinedseparately and the two volumes are added together.
NOTE In any case the largest achievable total volume is to be reported.7.3overall internal dimensions and overall volume7.3.1 General
Where the surfaces forming the boundaries of the cavity incorporate protrusions ordepressions，the planes used for measurement shall be those comprising the largestpercentages of the total areas of the surfaces. Holes in surfaces shall be disregarded whencalculating areas for this determination.
The following volumes or spaces shall be disregarded:
those occupied by removable items specified by the manufacturer as not essential for theoperation of the appliance, such as shelves or temperature probes;
those occupied by radiant heating elements if provided;
those occupied by minor irregularities in the cooking compartment walls，including coversover waveguides and lamps;
those occupied by turntables or reciprocating trays，their drive mechanisms and supportarrangements;
corner radi smaller than 10 mm at the intersections of the interior surfaces of the cookingcavity.
Dimensions are stated in millimetres.7.3.2overall height (H)
The maximum vertical distance in millimetres between the plane of the cooking cavity bottomand the plane of the cavity ceiling.
7.3.3overall width (w)
The maximum horizontal distance in millimetres between the planes of the cavity side walls.
7.3.4overall depth(D)
The maximum horizontal distance in millimetres from the plane of the inside surface of the doorwhen closed with the interlocks engaged to the plane of the rear cavity wall.
NOTE The overall dimensions of microwave drawers may be measured using the same principles.7.3.5overall volume of rectangular cavities
The overall volume is the total internal volume of the cavity in which cooking takes place and isexpressed as the product of H, W and D determined as above, divided by 10° and rounded tothe nearest litre.
7.3.6overall volume of non-rectangular cavities
At a complex shaped cavity, the following measuring method is considered as one alternativemeasuring method. Seal all openings of the cavity and fill water to the sealed cavity andseparately fill water to the concave space of the door cavity side.The volume is expressed tothe nearest litre.
8Determination of microwave power output
The measurement is made with a water load in a glass container. The water temperature isinitially below ambient temperature and is raised to approximately ambient temperature byheating in the microwave oven. This procedure ensures that the heat losses and the heatcapacity of the container have a minimum effect， but in any case a correction factor isintroduced. However, the procedure requires the water temperature to be measured accurately.