According to a regulating device without self-testing, the paper discusses the hardware circuit design and software design for detection instrument. The design of simulation power providing to regulating device and detection instrument is described in detail. 针对某调控装置无自检功能的弊端,论述了对该装置实现原位检测的检测仪的硬件电路设计及软件设计,阐述了供调控装置与检测仪使用的模拟电源电路设计。