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DigiMelt Melting Point Apparatus

The picture below shows a DigiMelt melting point apparatus. Like the Mel-Temp, this type of melting point apparatus uses long, thin melting-point capillaries. Unlike the Mel-Temp, it has a built-in digital thermometer and can record several data points.


Technique for Taking a Melting Point

Pack the capillary tube by pressing the open end gently into a sample of the compound to be analyzed. Crystals will stick in the open end of the tube.
The solid should fill the tube to a depth of 2-3 mm. Tap the bottom of the capillary on a hard surface so that the crystals pack down into the bottom of the tube.
Alternatively, put the end of the tube into the Tube Tapper spaces on the right edge of the DigiMelt, and hold the Tube Tapper button down.
When the crystals are packed into the bottom of the tube, place the tube into the slot behind the eyepiece on the Mel-Temp. Make sure the unit is plugged in, then turn it on.
Follow the directions printed on the front of the DigiMelt to determine the compound's melting point. If you do not know the expected melting point of your compound, a ramp rate of 10°C per minute should give you a rough first guess. You can then cool back down, choose a temperature slightly below the melting point, and use a ramp rate of 0.5 or 1°C per minute to refine your estimate.

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