My oven seemed to have developed a penchant for burning food.
I thought perhaps the temperature of the oven is higher than what is indicated on the dial. I tried reducing the cooking temperature by 25 degrees (so cook at 375, if the box says cook at 400). But the food still burned.
So I bought an oven thermometer to figure out what the temperature actually was. I made several measurements at different set temperatures to get an idea what the general relationship was between the set temperature on the dial and what the actual temperature of the oven (as measured by the oven thermometer). In each case, I waited at least ten minutes for the oven to reach the set temperature before making a reading.
What I found out was quite surprising. There is a marked difference between the set and actual temperature. Interestingly the discrepancy widens at lower set temperatures. Indeed the lowest measurement is at a set temperature of 200 degrees, but the actual temperature of the oven was about 330 degrees. This is a 130 degree difference! Wow! I am glad I know this now.