An Inexpensive Immersion Heater for an Oil Bath A small, inexpensive, immersion heater for an oil bath can be made from a 125-ohm, &watt resktor (Ohmite "Brown Devil"). Power is supplied from a variable transformer via a.length of lamp cord which has been soldered to the leads of the resistor. The device can heat 225 ml of l that temperature with a voltage paraffin oil to 150" in about 10 min, and will maintain the ~ i at setting of about 90 v. This heater is smaller, easier to make, and less messy to use than those made from a coil of nichrome wire, while retaining the advantage of rapid response to changes of voltage. At high voltage settings, it is necessary that the bath be stirred.
Volume 42, Number 1 I , November 1965
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