I. Overview MBY-5 type stopwatch Calibrator is a versatile, comprehensive time test automatic test equipment capable of mechanical stopwatch, electronic stopwatch, Analog electronic stopwatch, digital electric stopwatch, digital millisecond meter, various time relay and timer, and other timekeeping instruments test / calibration. This instrument uses a high-stability crystal oscillator as a time reference, and TTL IC with 89C51 microcontroller as the main component, there are six digital display, membrane switch operation, to meet JJG237-2010 "stopwatch test procedures" requirement, a ideal and practical stopwatch Calibrator. You can build a stopwatch Calibrator standard equipment, carry out the time class instrument test / calibration. Second, technical indicators 1. Measuring range 1ms ------ 99999.9s 2. stopwatch measurement error: ± 3ms electric stopwatch: Analog: ≤ ± 0.6ms 3. crystal oscillator accuracy: ± 5 × 10-7 three working conditions Ambient temperature: 0 ~ 40 ℃ Relative humidity: <80%