# Household Melting Point Standards

I'd like to accurately calibrate a digital thermometer I'm building in the range of $50^\circ$ to $120^\circ$ Celsius.

I'm aware that one can buy various chemicals that have melting points in this range, but are there any readily available household / pharmaceutical items I could use instead?

From what I have read, it looks like the two easiest candidates would be vanillin or Sodium acetate (Thanks Curt F.), but I'm not sure how one would go about creating a pure enough calibration standard at home.

• The boiling point of water is a good calibration point. Sodium acetate trihydrate has a well-known melting point at 58 &deg;C but I don't know if you count that as "household". – Curt F. Apr 13 '15 at 4:55
• @CurtF. So one would just boil vinegar and baking soda, then cool and reheat to find the melting point? That sounds pretty household to me. – nbubis Apr 13 '15 at 8:29
• – Loong Apr 13 '15 at 8:56
• nubis: true but (i) it would take a lot of boiling and (ii) I worry about purity. Without perfectly pure compounds, the melting point is not exact. – Curt F. Apr 13 '15 at 14:54

According to this cooking site, Crisco brand vegetable shortening melts between $\mathrm{47^oC-48^oC}$ (yes, I know $\mathrm{48^oC}$ is less than $\mathrm{50^oC}$, but it seems pretty close to me). The best way to use such a non-certified melting point "standard" like this is to use your thermometer side-by-side with a properly calibrated thermometer.
Vanillin may be your best bet (melting point of $\mathrm{81^oC - 83^oC}$). Again, using a calibrated thermometer to check the actual melting point would be the ideal situation.