Multi-Testers are:

Multi-Testers are:

• A. An instrument that measures only electrical conductivity.
• B. An instrument that measures both thermal and electrical conductivity to test diamonds and simulants.
• C. A device to measure refractive index only.
• D. A tool for determining hardness.

Answer: (B)

Dual testing of thermal and electrical conductivity is essential for identifying diamonds versus simulants. A multi-tester does both measurements in one instrument, which is why it’s the best choice. Diamonds have very high thermal conductivity, so they dissipate heat quickly when probed. However, some simulants—especially moissanite—can mimic that thermal behavior, which can lead to misidentification if you only rely on heat flow. The electrical conductivity test adds a second dimension: diamond behaves as an electrical insulator at room conditions, whereas moissanite and other common simulants have different electrical responses. By combining both tests, the instrument more reliably differentiates diamond from look-alikes. The other options describe tools that test only one property or a different property altogether (refractive index or hardness), which don’t provide the same reliable identification as the dual conductivity approach.

Dual testing of thermal and electrical conductivity is essential for identifying diamonds versus simulants. A multi-tester does both measurements in one instrument, which is why it’s the best choice. Diamonds have very high thermal conductivity, so they dissipate heat quickly when probed. However, some simulants—especially moissanite—can mimic that thermal behavior, which can lead to misidentification if you only rely on heat flow. The electrical conductivity test adds a second dimension: diamond behaves as an electrical insulator at room conditions, whereas moissanite and other common simulants have different electrical responses. By combining both tests, the instrument more reliably differentiates diamond from look-alikes. The other options describe tools that test only one property or a different property altogether (refractive index or hardness), which don’t provide the same reliable identification as the dual conductivity approach.