Inner diameter: 47mm±1.4mm
Height: 180mm±1mm
Height of anti-volatile cover of vessel: 66.8mm±1mm
Material: made of hard glass or other suitable inert materials
Shaft
Reciprocating shaft diameter: 6.0mm-8.0mm
Inner diameter: 23mm-26mm
Height: 100mm±1mm
Top nut height: 23mm±1mm
Bottom nut height: 18mm±1mm
Material: made of hard glass or other suitable inert materials
Motor
Specified range of reciprocating frequency: within ±5%
第七法（往复筒法）
装置由溶出杯、往复筒、电动机、恒温水浴或其他适当的加热装置等组成。除另有规定外，溶出杯和往复筒的形状尺寸见图11。
（1）溶出杯 平底筒状溶出杯由硬质玻璃或者其他适宜的惰性材料制成。溶出杯内径为47mm±1.4mm，高为180mm±1mm。溶出杯上配有防挥发盖，防挥发盖高度为66.8mm±1mm，上端外径为50.8mm±1mm，下端可与溶岀杯匹配，内径为38.1mm±1mm；盖上的中心孔供往复轴（直径6～8mm）穿过。中心孔两侧可设置数量不等的排气孔，排气孔的直径为3.9mm±0.1mm。溶出杯置恒温水浴或其他适当的加热装置中。
（2）往复筒 由硬质玻璃或者其他适宜的惰性材料制成。往复筒内径为23～26mm，高为100mm±1mm，底部放置筛网的圆筒状螺帽高为18mm±lmm，顶部螺帽高为23mm+1mm。往复轴与顶部螺帽于螺帽的中心点相连。螺帽中心点两侧可设置数量不等的排气孔。往复筒置于溶出杯中。
（3）往复轴和筛网 往复轴及其相关配件一般由不锈钢或其他适宜材料制成，筛网由不锈钢或其他惰性的材料制成。
（4）电动机 可驱动往复筒在溶出杯内做垂直往复运动，也可引导往复筒在水平方向移动。仪器的往复频率应可调节，并保持往复频率在品种项下规定的±5%的范围内变化。运行时，除往复筒平稳的垂直运动外，装置和实验室台面均不应出现明显移动、振荡或震动。
Inner diameter: 47mm±1.4mm
Height: 180mm±1mm
Height of anti-volatile cover of vessel: 66.8mm±1mm
Material: made of hard glass or other suitable inert materials
Shaft
Reciprocating shaft diameter: 6.0mm-8.0mm
Inner diameter: 23mm-26mm
Height: 100mm±1mm
Top nut height: 23mm±1mm
Bottom nut height: 18mm±1mm
Material: made of hard glass or other suitable inert materials
Motor
Specified range of reciprocating frequency: within ±5%
Inner diameter: 47mm±1.4mm
Height: 180mm±1mm
Height of anti-volatile cover of vessel: 66.8mm±1mm
Material: made of hard glass or other suitable inert materials
Shaft
Reciprocating shaft diameter: 6.0mm-8.0mm
Inner diameter: 23mm-26mm
Height: 100mm±1mm
Top nut height: 23mm±1mm
Bottom nut height: 18mm±1mm
Material: made of hard glass or other suitable inert materials
Motor
Specified range of reciprocating frequency: within ±5%
Apparatus 3 (Reciprocating cylinder).
The assembly consistsof a set of cylindrical, flat-bottomed glass vessels; a set ofglass reciprocating cylinders; inert fittings (stainless steeltype 316 or other suitable material) and screens that are madeof suitable nonsorbing and nonreactive material, and thatare designed to fit the tops and bottoms of the reciprocatingcylinders; a motor and drive assembly to reciprocate thecylinders vertically inside the vessels, and if desired, indexthe reciprocating cylinders horizontally to a different rowof vessels. The vessels are partially immersed in a suitablewater-bath of any convenient size that permits holding thetemperature at 37 + 0.5 C during the test. No part of theassembly, including the environment in which the assembly isplaced, contributes significant motion, agitation, or vibrationbeyond that due to the smooth, vertically reciprocatingcylinder. A device is used that allows the reciprocationrate to be selected and maintained at the specified dip rate,within + 5 per cent. An apparatus that permits observation ofthe preparations and reciprocating cylinders is preferable. Thevessels are provided with an evaporation cap that remains inplace for the duration of the test. The components conformto the dimensions shown in Figure 2.9.3.-4 unless otherwisespecifed.
