Ohaus
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Ohaus Guardian 5000 Hotplate 7" x 7" with Ceramic Top Kit 120V, one model. Heating and stirring belong together because heating without stirring is heating unev
30981780
Ohaus Guardian 5000 Hotplate 7" x 7" with Ceramic Top Kit 120V. Heating and stirring belong together because heating without stirring is heating unevenly.
A ceramic top resists acids, cleans easily and tolerates spills, which is why it is standard for chemistry. It also heats a little more slowly than metal. An aluminium top conducts heat faster and more evenly, and is the better choice for a heating block or a large flask, but it stains and corrodes where a ceramic top would not.
The number on the display is the plate, not the liquid. The gap between them depends on the vessel, the volume and the room, and it can be tens of degrees. Where the sample's temperature is what matters, a probe in the liquid feeding back to the controller is the only honest way to run it.
A hot plate stays dangerously hot long after it is switched off and most have no way to show it; treat a cold-looking plate as hot until it is proven otherwise.
Supplied in one model.