| 摘要 |
A tester for testing hardness of a tablet formed from a compact of pharmaceutical powders. The tester has a spherical indenter suspended from a wire to impact the tablet to evaluate the hardness thereof. The tablet is contained in a split die holder which can regulate the die wall pressure. The indenter is supported against an electromagnet and, when released, swings through a controlled arc and impacts the tablet. The indenter passes three photocells in its downward arc toward the tablet, and the last photocell activates both a timing device connected to the first two photocells and a shutter plate to prevent reimpact of the indenter with the tablet face. After impact with the tablet face, the indenter is timed as it rebounds past the first two photocells. Since the distance between the first two photocells is known, the time it takes the indenter to travel between the first two photocells is sent to a computer and the velocity is calculated. The velocity is converted into rebound height of the indenter and, from this information, a calculation of the indentation hardness and the strain index is made. |
