Low-cost programmed oven temperature controller

Fine Instruments Shop, College of Sciences and Technology, East Texas State University ... to start a t some pre-determined initial temperature and th...
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Low-Cost Programmed Oven Temperature Controller Gerald D. Clubine Fine Instruments Shop, College of Sciences and Technology, East Texas State University Commerce. TX 75428

Laboratory work with gas chromatographs sometimes requires that the oven have its temperature controlled such as to start a t some pre-determined initial temperature and then increase from this temperature at a precise rate of change until a pre-determined final temperature is reached. Until now this meant either having a more expensive gas chromatograph or ~urchasinc remote controller for about .. a oroerammed . $700-S1000or more. Hereat East Texas State University we huilt our own remote mntn)ller unit for about 9425. This was with no breaks on parts cost since all parts had to be purchased through a costly state purchasing system, and it included an extra RTD '18 in. stainless steel encased probe for $65. The basic unit cost about $360. The controller has three switchselectable modes of operation: (1) isothermal, (2) programmed hold, and (3) programmed clear. I t has ten-turn locking set