WANG Yi-zhou1, DUAN Chang-sheng2, WU Kang1, JIAO Hai-ni1, CUI Shao-ying1, ZHANG Jun-qi1
1.Beijing Oriental Institute of Measurement and Test,Beijing 100086, China
2.Heilongjiang Huaan jingyi Metrology Technology Institute Co., Ltd. Harbin, Heilongjiang 150046, China
Abstract：A high-precision DC&AC digital ammeter with range 10A to 100A is introduced, which is based on fluxgate current sensor, precise resistor, 20-bit A/D converter and Raspberry Pi. Hard real time kernel and Hample Filter is applied to avoid the shortcomings of the Raspberry Pi in real-time hardware, highlighted with powerful calculate ability and flexibility. The ammeter achieved precise measurement with the relative error below ±0.02%, and is given the ability of storing measurement result, remote connection, rapidly software upgrading. The error level in theory is investigated in terms of circuit design and software design, keeping consistency with the experimental result.
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2019, Vol. 40 
