国产免费无遮挡吸奶头视频-小尤奈爆乳在线18分钟-国产成人无码精品久久久性色-欧美白妞大战非洲大炮

(1) Testing items are flexibly optional: K⁺，Na⁺，Cl^-，Ca²⁺, pH or any of them
(2) Liquid distribution valve is automatically segmented and flushed throughout the whole process, which is not easy to block
(3) Double parameters of slope and mean deviation are corrected to ensure linearity and accuracy
(4) Calibration solution and waste solution are contained in the closed containers, which reduces the risk of biological pollution and meets environmental protection requirements
(5) Optional autosampler provides 1 emergency test position, 3 quality control test positions and 39 sample test positions