Air pressure calibrators are instruments which provide standard pressure signal for Automatic Weather Stations. ( AWS) .At present,the calibrators applied for meteorological measurement are just capable of outputting one kind of pressure signal and using in only one type of AWS.Therefore,aiming at this problem,a new type of air pressure calibrators which are of high-preci-sion was designed.They can output through three channels( RS232,analog voltage,trigger pulse) simultaneously but be non-interfer-ing for one another.They adopted single chip microcomputers as the dominant control and CPLD as their expansion port.The pres-sure signal from channel RS232 was attained by using USART of single chip microcomputer.The trigger pulse mode can be pro-duced by CPLD after receiving the trigger signal from AWS on basis of timing sequence of sensor.Analog voltage generates from u-sing high-precision DAC,and low offset voltage ( 3μV) .The bus isolation and DC-DC measures guarantee each channel not to in-terfere with one another.Tests show that the air pressures of the three electric parameters are 500~1 100 hPa,which are the scope of measurement of AWS.The maximum error of this kind of calibrator is 0.02 hPa.It is much lower than the maximum error of AWS ±0.3 hPa.This new kind of calibrator is measurement and calibration for different models of AWS.%气压检定仪是一种为自动气象站提供标准气压信号的仪器。针对目前气象计量业务应用的检定仪输出气压信号单一不能兼顾不同型号自动站的问题，设计一种高精度、多通道（ RS232、模拟电压、触发脉冲）同时输出而互不干扰的新型气压检定仪。采用低功耗单片机为主控、CPLD扩展I／O口的硬件架构。 RS232通道气压信号利用单片机的USART编程产生；触发脉冲通道利用CPLD模拟传感器的时序，收到自动站的触发信号后分频产生；模拟电压通道选用高精度DAC和极低失调电压（3μV）运放产生。总线隔离和DC－DC措施保证了各通道互不干扰。测试表明：3个通道输出的气压信号范围均为500～1100 hPa，覆盖了自动站的测量范围。最大误差0．02 hPa，远低于自动站的最大测量误差±0．3 hPa，为不同型号的自动站提供了一种综合的计量检定仪器。
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