在医疗电子仪器及彩电中，常常用到石英晶体，因为它具有极高的品质因数，Q值可达10‘～10‘，因此当对振荡器频率稳定度要求甚高时，一般都采用石英晶体取代LC谐振回路，构成石英晶体振荡器，使它的频率稳定度达到10－‘～IO“数量级，石英晶体在电子线路上起着至关重要的作用 In medical electronic devices and color TVs, quartz crystals are often used because they have a very high quality factor. The Q value can be as much as 10’ to 10’. Therefore, when the frequency stability of the oscillator is required to be very high, quartz is generally used. The crystal replaces the LC resonant tank to form a quartz crystal oscillator, so that its frequency stability reaches the order of 10′′ to IO′, and the quartz crystal plays a crucial role in the electronic circuit.