This paper firstly makes experience study of grain flow dynamic measurement for combines in china . piezoelectric crystal sensor used in impulse measurement method is a try and has not been presented in any reports 本文在国内率先进行了谷物流量动态在线测量方法的试验研究，并尝试性地将压电晶体传感器用于冲量式谷物流量测量方法中，这在国内外均未见报道。
In this paper , two kinds of grain - flow - measurement - systems for combine harvesters are developed in laboratory , radiometric sensor using the principle of the absorption of y - rays by grains and piezoelectric crystal sensor using the principle of impact 关于谷物流量在线测量的研究方法，有光电、冲量法、核辐射及电容传感器等。这些测量方法虽各具特色，但至今在应用上仍还有各自的缺陷需要解决。
