Thursday, January 29, 2009

First glaze firing of 2009

First firing of 2009 is done. I offer the sake and salt to the kiln god for the first firing of the year. I decided to fire the kiln yesterday despite the winter storm warning, while trusting the weather man again, he said, "the wind is not the issue today." Wrong! The wind started gusting crazy after the sunset, when it was too late but continue firing. It stalled the kiln for couple hours from raising the temperature, and the oxyprobe reading was all over the place from the oxidation to the reduction. I peeked the kiln today, might not be as bad as I thought yesterday. I hope several custom orders come out good tomorrow.

Good news out of this firing. Last December, the oxyprobe meter stopped working. Since then , I bought the multimeter (UEI DM383B) off the ebay, and fired with it along with a friend's oxyprobe in December . It read the atmosphere the same, but the temperature was off 1 readings at the beginning and off 2 reading toward the end, which made me nervous.

I have been toying with the broken oxyprobe meter with a multimeter for a while. Am I familiar with electronics? No. I have no idea how these diodes work. I can check and read the meter and solder things, though. It was broken and I had no thing to lose. I checked reading of the resistances, and replaced two diodes which I thought the reading was wrong. No, my reading of the diode was wrong.

I found a repair manual for multimeter, which lead to the IC chip, which the oxyprobe meter have three, and ordered the same ones ($5 dollars!) on the web store . Replacing them was easy, and Bingo! IC for the LCD was the problem. Also I messed up the calibration by turning the knobs inside.

The oxyprobe actually worked after successfully calibrated with friend's meter(meaning I get the same reading). I cannot believe I actually fixed the meter!


marina jason said...
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