我校实验室有12台江苏靖江无线电器材厂生产的J0203型打点计时器,投入使用后发现这些打点计时器个个都有毛病。表现为,第一次使用时一开始工作正常,打上两米左右纸带后就不能工作,一开电源,只见振动片嗡嗡响,就是打不上点。经过检查发现,这些仪器的共同 The laboratory of our school has 12 J0203 dot counters manufactured by Jiangsu Jingjiang Radio Equipment Factory. After they were put into use, they found that all these timers were faulty. The performance was that the first time they started working properly, they could not work after putting on a tape of two meters or so. When they turned on the power supply, they only saw that the vibrating film buzzed. After inspection, it was found that these instruments are common