A temperature measuring apparatus including a circuit capable of analog-converting without using an operational amplifier, a centrigrade temperature value directly detected as an electric signal to a fahrenheit temperature value and being devised so as to digitally display a measured temperature selectively...http://www.google.com.hk/patents/US4783175?utm_source=gb-gplus-share專利 US4783175 - Temperature measuring apparatus capable of displaying measured temperatures in different temperature scales
