0-20 instrument Bragg-Brentano geometry counter& pre-amplifier divergence scatter counter driven at 28per min slit slit sample driven at receiving H.T.supply, slit chart recorder 寻 and counting X-ray electronics tube powdered and sample goniometer hand drive shield .goniometer 20 position Goniometer(测角仪)2 instrument Goniometer (测角仪) Bragg-Brentano geometry