The “Melt-O-Matic” – A Digital Melting Point Apparatus

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A common technique in organic chemistry is to determine the melting point of a specimen. While commercial options exist, [kymyst] decided to build one with similar (or better) functionality, and managed to keep it under $100. The basis of his rig is a 60W soldering iron. He simply replaced the normal soldering tip with an aluminum heating block that holds the capillary tubes and temperature probe. Two small fans are used to quickly cool the heating block, allowing fairly quick measurement times. It should be noted that building a project like this one will mean working with wires that carry 220V (or 115V, depending on your country). Please use proper precautions.

In case organic chemistry is on your list of ‘to learns’, [kymyst] included a nice writeup of the determination of melting points. It’s a great primer for those interested in learning more.

Using this setup, [kymyst] gets readings of ±0.1 °C. He mentions the possibility of adding a webcam for determining melting point automatically, something that would make this system competitive with much more expensive hardware.

The last time we saw one of these it used a hot glue gun as the heating element.

Comments

  1. EccentricElectron says:

    66 It should be noted that building a project like this one will mean working with wires that carry 220V (or 115V, depending on your country). Please use proper precautions. 99

    Oh please, please no – spare us the health warnings. First, low voltage soldering irons are available so it’s not even accurate. Second there are plenty of other associated risks (handling organic chemicals, vapours from heating — the rig EVEN gets HOT!!) so why pick just one at random?

    • kymyst says:

      Because electrocution is instantly fatal. Organic vapours in the minute quantities emitted from this apparatus will take a long time to kill you, and burnt fingers even longer.

  2. John says:

    Should it not be possible to find the melting point automatically anyway without a webcam?

    The input of energy with no temperature increase is the melting point, that is what melting is, the change of state and energy is taken to perform that change.

  3. Jeff Nichols says:

    Type K Thermocouples are usually +-1.5C, so unless he’s done some serious calibration, I think he’s been fooled by an ebay “deal”.

    • somun says:

      If you read through the instructable you’ll see his calibration method. Looks pretty solid at first glance.

    • kymyst says:

      Please read the section “CALIBRATION OF THE INSTRUMENT” and you will see that the calibration procedure is quite “serious”. Of course the thermocouple readings need to be properly calibrated. Why do you make such stupid comments without reading the whole item ?

  4. mistbooster says:

    “It should be noted that building a project like this one will mean working with wires that carry 220V (or 115V”

    Or 230V, 400V or 440V depending on the country or available wires :P

  5. fartface says:

    So what is the melting point of a frog?

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